It has been said to be cruel. In so far as we knowingly, and of set

purpose, occasion the animal pain, cruel it undoubtedly is; but it is

cruelty with an aim that is truly benevolent, and the object of our

benevolence is the animal upon whom the cruelty is practised.

One word of advice is needed. The forced exercise must be commenced early.

In the later stages, when the stage of congestion has passed from that

to the acuter stages of the inflammation and the outpouring of the

inflammatory exudate, then forced exercise cannot be safely commenced. The

loss of adhesion between the pedal bone and the horny box, which we know to

be then existent, negatives its advisability.

By many it is advised to always remove the shoes. From what we have already

said, it will be seen that this is not our practice. But one argument

in favour of so doing appears to us to carry weight, and that is that

'dropping' of the sole is probably prevented from becoming so marked. That

condition, however, is entirely dependent upon the changes occurring within

the horny box. It is bound to occur with the animal shod or unshod, and

to reach a stage when only contact with the ground prevents its further

descent. The complication then sometimes following--namely, penetration of

the sole by the bone, is not prevented by having the shoes removed. It may,

in fact, be thus rendered more likely.

Internal treatment consists in the exhibition of suitable febrifuges and

the administration of a dose of aloes.

With regard to the wisdom of the latter proceeding, opinion seems to be

divided. Personally, we hold an open mind concerning it. This much is

certain: in many cases of laminitis--those cases which have their origin

in overfeeding with an irritating food--there is already a strong

predisposition to enteritis. The administration of aloes in this case

is extremely apt to induce a fatal super-purgation. Aloes is, again,

contra-indicated when the laminitis is a result of excessively long

journeys, and the patient is already greatly exhausted. Neither can it be

advocated in the laminitis occurring as a sequel to septic metritis or to

pneumonia.

On the other hand, when the disease has occurred as a result of long

standing in the stable and an overloaded condition of the bowels, or where

one full meal of some constipating food, such as whole wheat, pea or bean

meal, wheat or barley meal, has occasioned the attack, then a dose of aloes

at the commencement of the treatment is productive of good.

Suitable febrifuges are found in potassium nitrate, potassium chlorate,

sodium sulphate, or magnesium sulphate, either of which or a mixture of two

or more of them, the animal will readily take in his drinking-water.

The administration of sedatives is also indicated. In this connection

aconite will be found most useful. More especially in the early stages of

the disease, when pain is excessive and the temperature high, will its

good effects be noticed. This also the animal will often take in his

drinking-water. We have been in the habit of so prescribing the B.P.

tincture in 1/2-dram doses three times daily. By its use the temperature is

rapidly lowered, the pulse reduced in number and in fulness, and the pain

in some instances perceptibly diminished. With others hypodermic injections

of morphia and atropine have given equally satisfactory results.

Needless to say, good nursing is a _sine quâ non_. During the first

stages of the fever a light and easily digested diet should be

allowed--bran-mashes, roots and grass when obtainable, and a carefully

regulated supply of water. The animal should be warmly clothed and the box

well ventilated, even to the opening of the doors and windows. Only in this

way is pneumonia as a sequel sometimes prevented. The patient's comfort

should be attended to in providing him with a suitable bed. Anything in

the shape of long litter should be avoided. When nothing else is at hand,

litter that has already been broken and shortened by previous use is best.

With this the box floor should be thickly covered, and matting of the

material prevented by constant turning. A good bed for the horse with

laminitis is peat-moss mixed with short straw. This, without being

dragged into irregular heaps, remains springy and elastic with but little

attention. Better than all, however, especially with good weather, is an

open crewyard. Here the animal has an abundance of fresh air, has a bed

that is always soft, and has plenty of room in which to get up and down

with some degree of ease.

Leaving the dietetic and medicinal, we may consider other treatments of

laminitis that come more particularly under the heading of operative.

The first matter that here demands our attention is that of allowing the

exudate to escape at the sole. If after the expiration of three or four

days pain and other symptoms of distress continue, then it may be judged

that the inflammatory exudate has made its appearance. Operative measures

allowing of its escape, though not giving absolute ease, do undoubtedly

relieve the more marked expressions of suffering, and should be at once

determined on. To do this completely it is necessary to cast the animal.

The sole is then thinned at the toe with the drawing-knife until the

sensitive structures are reached. A flow of yellow and sometimes

blood-stained discharge is immediately obtained, and the sole itself found

to be underrun to a considerable extent. An opening sufficiently large to

admit of free drainage (about the size of a half a crown-piece) is made,

the wounds antiseptically dressed, and the hobbles removed.

If showing an inclination to do so, the animal should then be allowed

to remain and rest. In one instance in which we so operated (a case of

laminitis in the hind-feet alone), the relief given was at once manifested.

For three days previously the animal had remained standing in agonizing

pain. On the fourth he was cast, and the discharge--partly inflammatory

exudate, and partly a sanious foetid pus--liberated. The hobbles were

removed, and the animal allowed to remain down while our attention was

drawn to another case. This attended to, we walked back to the field

where, our first patient was lying. His breathing, but a short time before

distressedly short and catching, was now so slow and deeply regular that

for one brief moment the thought flashed across our mind that he was dead.

He was in a _profound_ sleep.

Other operators sometimes give the exudate escape while making the grooves

in what is now known as 'Smith's Operation.'

In this operation the hoof is so grooved as to allow of its expansion, so

relieving the pressure on the sensitive structures within it. Incidentally,

the inflammatory exudate is given exit.

[Illustration: FIG. 120.--DIAGRAM OF HOOF SHOWING THE POSITION OF THE THREE

GROOVES MADE IN THE TREATMENT OF LAMINITIS.]

The animal is cast, the shoes removed, and three vertical grooves made

in the wall. The first is cut down the centre of toe, extending from the

coronet to the ground surface. The second is made to the right of this, and

the third to the left, each following the direction of the horn fibres, and

each distant about 2 inches from the first (see 1, 2, and 3, Fig. 120).

Each of the grooves must run completely from the coronary margin to the

ground surface, and each should be carried through the substance of the

horn until the horny laminæ are reached. This done, the underneath surface

of the foot is grooved at the white line (see curved groove 4, Fig. 121)

in such a manner as to entirely isolate the two pieces of horn _a_ and _b_

from the remainder of the hoof.

Expansion of the horny box is thus brought about, while at the same time

the semicircular groove at the toe is made deep enough to allow of the

escape of the exudate.

If thought wise by the operator, the two pieces of horn _a_ and _b_ may be

isolated, and the exudate given exit by making the fourth groove in the

position of the dotted lines in Fig. 120--that is to say, at the lowermost

portion of the sensitive structures. By this means the sole will be left

intact.

[Illustration: FIG. 121.--LOWER SURFACE OF FOOT SHOWING POSITION OF THE

GROOVES MADE IN THE TREATMENT OF LAMINITIS.]

Fuller instruction for making the grooves and the instruments required will

be found described in Section C of Chapter X.

The animal should be afterwards shod, and the bearing on the portions

_a_ and _b_ of the wall removed. Almost immediate relief is afforded the

patient.

_Recorded Cases_.--1. 'On the evening of September 28 last, I was called

rather hurriedly to attend a posting-horse which had just arrived from a

twenty-one miles' journey, and was said to be "very ill." I lost no time in

proceeding to the spot, and found my patient "very ill" indeed. No need for

long consideration as to diagnosis; the symptoms showed at once that I had

an uncommonly severe case of acute founder before me. On examination I

found the pulse was 120, the respirations 100, and the thermometer 106° F.

The poor brute could not move, the fore-legs were well out before, and the

hind-legs thrown back behind; in fact, he was, as one might say, propping

himself up with his four legs!

'On examining his feet, I discovered what I had never either seen or heard

of before--namely, _blood freely oozing out_ at the coronet of all four

feet; if anything, the hind-feet were the worst, and, showing that this

bloody discharge at coronets had commenced during progression and before

he was stabled, the inside of the thighs were all shotted over with blood,

which had been thrown up by his feet while he was trotting or walking. He

was completely soaked all over with perspiration.

'My prognosis could not well be otherwise than unsatisfactory. I resolved,

however, to do all I could to relieve the poor suffering brute. As a matter

of course, jugular phlebotomy was utterly impracticable; so, to relieve the

pressure in the feet, I had him (after, with extreme difficulty, removing

the shoes) bled, or rather opened, at all four toes, and hot poultices

applied. On opening the off-side toe, in both hind and fore feet, I found

an escape of very dark-coloured blood, with a great many bubbles of gas,

thus showing that the destructive process was fairly established in the

two bony extremities mentioned. The near fore and near hind feet showed no

signs of gas-bubbles on being opened at the toe.

'I gave a laxative in combination with a diffusible stimulant, and ordered

doses of aconite and potassium iodide; I also applied strong sinapisms to

each side, immediately behind the shoulders. After three hours I found my

patient rather easier; respiration about 90, and temperature 104°; willing

to take a little water, and even attempted to take some hay. Ordered

continued applications of hot water to the poultices at feet, and

clothed him up for the night. Next morning there was little improvement;

respirations over 80, and temperature 103.5°. Continue same treatment.

Second morning, horse apparently easier; temperature 102.5°, but very

difficult respiration; laxative had operated during the night; ordered

diffusible stimulants. About two hours and a half after my last visit, the

horse turned round in his stall and dropped down dead!

'_History of the Horse_.--He belonged to an extensive horse-hiring

establishment; was purchased a short time before for £60--a long price for

a post-horse--had recently suffered and been off work from some "severe

cold"; was taken out, and did forty-seven miles of a journey the day

_before_ I saw him; on forenoon of the day on which he was attacked he did

two or three short turns, and then twenty-one miles of a journey in the

afternoon, during which he became so ill as scarcely to be able to conclude

the twenty-one miles; this was the last turn he was to do. He was a grand

stepper, and no doubt was pushed a little during this final journey, as

the driver intended, after a short rest, to finish off with the twenty-six

miles between this and home. With the short turns on the second forenoon,

this would have been over 100 miles in less than two days, with a horse

just out of a _severe cold_.'[A]

[Footnote A: _Veterinary Journal_, vol. xvii., p. 314 (A.E. Macgillivray).]

2. 'Whilst attending a patient on a farm on September 5 last my attention

was called to a cart-horse, five years of age, that had been castrated in

the standing position by a travelling castrator about ten days previously.

'I found the animal presenting the following symptoms: Head down, blowing

hard, very dull, and disinclined to move, temperature 105° F., hard, rapid,

slightly irregular pulse, membranes injected, appetite lost; scrotum,

sheath, and penis tremendously swollen, castration wounds unhealthy, and

exuding a thin, reddish-brown discharge of a most foetid odour.

'The next day well-marked symptoms of laminitis were present. I finally

ceased attending him about the middle of October, and at the end of that

month he was turned out for the winter.'[A]

[Footnote A: _Veterinary Record_, vol. xiv., p. 649 (Charles A. Powell).]

3. 'On July 8 an interesting case of laminitis came under my notice. The

subject was a mare, eight years old, which had been running on the common

here for some months, and was taken up on the night of July 2 by a boy,

who did not observe anything amiss with her. The following morning, on the

owner going to the stable, he found the animal in great pain, and at once

sent for me. I discovered her to be suffering from laminitis, and saw her

again in the evening, when she was much worse. The attack proved to be a

most severe one.

'The owner informed me that she had not been allowed any corn for two

months, and that she had no distance to travel on the road from the common.

'Though on such a poor pasture, the mare was very fat; she had never been

unwell before this attack.

'This is the first case I have seen of laminitis occurring when the animal

was on grass.'[A]

[Footnote A: _Veterinary Journal_, vol. ix., p. 176 (W. Stanley Carless).]

B. CHRONIC.

1. CHRONIC LAMINITIS.

_Definition_.--A low and persisting type of inflammation of the sensitive

structures of the foot, characterized by changes in the form of the hoof,

and incurable pathological alterations within it.

_Causes_.--Chronic laminitis more often than not is a sequel to the acute

form we have just described. With an attack of acute laminitis that defies

treatment, and does not end in resolution in from ten days to a fortnight,

then the chronic form may be expected.

The brittle horn, convex sole, and other changes we have described under

Pumiced Foot may, however, be regarded as a chronic laminitis, and this

condition, as we have already indicated in Chapter VI., may run a course

slow and insidious from the onset.

_Symptoms_.--When the disease arises without previous acute symptoms, the

first thing noticeable is an alteration in the gait. The animal begins to

go feelingly, especially when first moved out from the stable. Our opinion

is asked as to the cause of the lameness, and an inspection is made. With

the changes in the form of the hoof as yet wanting, we have nothing to

guide us, and other causes for the lameness suggest themselves, probably

corns. Evidence of these is not forthcoming, and we in all probability

withhold our opinion until a later visit. On the second or a subsequent

call we are perhaps lucky enough to find our patient down. Diagnosis is

then rendered easier. Made to rise, the animal stands in the attitude we

have described as indicative of laminitis. We have him walked and trotted

out. The symptoms of tenderness disappear, and the animal soon goes fairly

sound. He is, in fact, workable--that is, by anyone who is careless as to

the comfort of his beast.

When following an acute attack, we have the most marked symptoms of pain

and distress, somewhat abating after the second or third week. The walk,

however, is still painful, and, for a short time after rising from the

ground, even difficult.

In short, in both cases we have the horse going on his heels, with a walk

that is painful, and with symptoms of pain that are most apparent when

moved on after a rest.

Later, the changes in the form of the hoof begin to appear. It seems to

have lost its elasticity, and is seen to be dry and chippy, and to have

become denuded of its varnish-like outer covering.

In addition, it is of largely altered shape. The toe, by reason of the

animal walking on his heels, and by reason of an increased growth of horn,

becomes elevated, so that the front of the wall, instead of forming an

obtuse angle with the ground, comes to run very nearly horizontal with

it. The horn of the heels, as compared with that of the toe, takes on an

increased growth. The same thing we have already indicated as happening at

the toe, though in lesser degree. Taken together, this increased growth of

horn at the toe and at the heels has the result of lengthening the diameter

of the foot from before backwards, the transverse diameter remaining more

or less normal. The hoof thus loses its circular build, and comes to

approach nearer an elongated oval.

[FIG. 122.--FOOT BADLY DEFORMED AS A RESULT OF CHRONIC LAMINITIS.]

At this stage, too, the pathological 'ribbing' of the hoof is observable.

The outer surface of the wall becomes marked with a series of ridges

encircling the hoof from heel to heel (see Fig. 81, which illustrates a

moderate deformity of the hoof occurring after laminitis). In the badly

laminitic hoof, however, this deformity is largely increased, until in some

cases the shapeless mass can hardly be likened to a foot at all (see Fig.

122).

The inferior or solar surface of the foot also offers certain changes for

our consideration. The first thing that strikes one is the convexity of the

sole. This, as we have already pointed out, is due to descent of the os

pedis, and the highest point of the convex portion is that immediately in

front of the apex of the frog. Here the horn is sometimes found to be quite

yielding to the finger, is excessively thin, and is more or less granular

and inclined to break up under manipulation. As a consequence, any rough

use of the drawing-knife, or an accidental wounding with sharp flints or

stones, leads to exposure of the sensitive structures and local gangrene.

With the horn of the sole thus deteriorated by reason of excessive and

continued pressure upon the parts secreting it, it is not surprising to

find that, in many cases, actual penetration of it with the os pedis

occurs. It is the anterior portion of the inferior margin of the bone that

makes its appearance, and shows itself as a small semicircular white or

dark gray line on the sole.

[Illustration: FIG. 123.--SOLAR ASPECT OF FOOT WITH CHRONIC LAMINITIS,

SHOWING ITS ABNORMAL OVAL SHAPE FROM BEFORE BACKWARDS, AND THE EXCESS OF

HORN GROWING FROM THE WHITE LINE IN THE REGION OF THE TOE.]

Exposure of the bone is soon followed by its necrosis, in which case the

wound takes on an ulcerating character. From it there is a discharge of

pus, black in colour and offensive in smell, and, protruding from the

opening, are excessive granulations of the remains of the sensitive sole.

The 'white line,' so apparent when a normal foot is cleaned with the knife,

can no longer be sharply distinguished from the surrounding horn, while in

some cases the horn composing it takes on an abnormal growth at the toe

(see Fig. 123). This adds still further to the abnormal lengthening of the

antero-posterior diameter of the foot already mentioned.

In other cases horn in this position is altogether wanting, and in its

place is a well-defined cavity, into which the blade of a knife can be

readily passed. This cavity is bounded in front by the original wall of the

hoof, and is here lined by a degenerated and hypertrophied growth of the

horny laminæ. Posteriorly the cavity is bounded by the front of the os

pedis, and is lined by a thin growth of horn secreted by the keratogenous

membrane covering the bone. Superiorly the cavity is quite narrow,

and extends to near the lower surface of the coronary cushion, while

inferiorly, at its open portion, it is often 1/2 inch to 1 inch wide.

Laterally it extends on each side of the toe to the commencement of the

quarters.

[Illustration: FIG. 124.--LONGITUDINAL SECTION OF A FOOT WITH LAMINITIS OF

THREE WEEKS' STANDING. On the anterior face of the cavity, in front of

the os pedis, are thickened horny laminæ. Due to the sinking of the bony

column, the os pedis has perforated the horny sole.]

Exploration with a director, or with the blade of a scalpel, removes from

the opening a dry detritus. This is composed of the solid constituents

of the escaped blood, the dried remains of the inflammatory exudate, and

broken-down fragments of cheesy-looking horn. The size to which the cavity

may sometimes extend is illustrated in Fig. 124. The thickened horny laminæ

forming the anterior boundary of the cavity are here depicted, together

with commencing perforation of the horny sole by the os pedis. It is this

cavity which, when opened at the bottom and discharging its mealy-looking

contents, is known as seedy-toe, for a further description of which see p.

293.

The lameness occurring with chronic laminitis does not always persist. As

time goes on the sensitive structures accommodate themselves to the altered

form and conditions of the horny box. In certain situations--namely, where

pressure is greatest--the softer structures become atrophied, and sometimes

even wholly destroyed; while in other positions the changes in form of the

hoof tend to increase in size of its interior, with a consequent diminution

of pressure upon, and increased growth of the structures within it.

_Pathological Anatomy_.--In detailing the changes to be observed in chronic

laminitis, we take up the description where we left it when dealing with

the pathological anatomy of the acute form. The alterations to be met

with are best observed by taking a foot so diseased and making of it two

sections--one longitudinal, from before backwards; the other horizontal,

and in such a position as to cut the os pedis through at its centre.

These sections will expose to view the cavity formed by the pouring out of

the exudate, and its full extent may be noticed by examining the sections

alternately. Taking the horizontal section first, it will be seen that

the hollow space extends wholly round the toe, and as far back as the

commencement of the quarters. In the latter position one is able to observe

laminæ still in their normal positions and condition. At the toe, however,

the horny and secretive laminæ are widely separated, and the space between

them filled with a yellow, semi-solid material, the remains of the

inflammatory exudate and new horn secreted by the keratogenous membrane.

The laminæ, both horny and sensitive, are greatly enlarged. This is a

hypertrophy, resulting from the continued effects of the inflammation, and

leads in time to the formation of laminæ quite three or four times their

normal size. It is this hypertrophy of the laminæ and the pressure of the

exudate that causes the bulging and increased growth of the horn at the toe

(see Fig. 125), and contributes towards the oval formation of the foot we

have mentioned before.

[Illustration: FIG. 125.--LONGITUDINAL SECTION OF A FOOT WITH LAMINITIS OF

SEVERAL YEARS' DURATION.]

In the longitudinal section the first thing noticeable is the change

in position of the bones, more especially in that of the os pedis. The

circumstances we have mentioned before--pressure of the exudate upon it in

front and tension of the perforans on it behind--have caused it to assume

a more upright position than is normal, so much so that in a bad case the

front of the bone becomes quite vertical. This vicious direction the other

bones of the digit follow (see Fig. 125).

Consequent upon the displacement of the bone, the plantar cushion, by

reason of the continued pressure thus put upon it, becomes atrophied, while

its hinder half is, as it were, squeezed into taking up a position

more posterior and higher in the digit than normally it should. The

horn-secreting papillæ covering its inferior face thus become directed

backwards sooner than downwards, in which way we account in some measure

for the noticeable increase of horn at the heels.

_Treatment_.--Chronic laminitis is incurable. Treatment must therefore be

directed towards the palliation of such conditions as are present, with

the object of rendering the the animal better able to perform work. When

perforation of the sole has occurred, with the attendant formation of pus

and necrosis of the os pedis, it is doubtful whether treatment of any kind

is advisable. There are on record cases of this description, where careful

curetting of the exposed and necrotic portions and the after application of

antiseptic dressings, held in position by a plate shoe or a leather sole,

has been followed by good results, and the animal restored for a time to

labour. In our opinion, however, early slaughter is the most economical

course to adopt, and certainly the wisest advice to give to the ordinary

client.

When perforation of the sole is absent, and when serious alteration in the

shape of the horny box has not occurred, then the most simple treatment is

to put the animal straight away to slow work, with the feet protected by

suitable shoes.

Here, again, the most useful shoe is the Rocker Bar (Fig. 119). The broad

web and deep seating gives ample protection to the convex sole, and with

the ease in distributing his weight that this shoe affords the animal is

able to perform slow work on soft lands with some degree of comfort.

Should the growth of the horn at the toe and at the heels be unduly

excessive, then our attention may be directed towards reducing it to some

approach to the normal. This is accomplished by removing with the rasp and

the knife those portions indicated by the dotted lines in Fig. 127. Here it

will be seen that the bulk of the horn removed is that protruding at

the toe. After this the animal should again be suitably shod. In this

connection it should be noted that the fact of the animal walking largely

on the heels tends to a forward displacement of the shoe. This must be

prevented by providing each heel of the shoe with a clip, after the manner

shown in Fig. 128; or, in the case of a bar shoe, supplying it with a clip

at the centre of the bar.

[Illustration: FIG. 126.--DIAGRAM ILLUSTRATING THE ABNORMAL GROWTH OF HORN

AT THE TOE AND HEELS OF THE FOOT WITH CHRONIC LAMINITIS.]

[Illustration: FIG. 127.--THE SAME FOOT AS IN FIG. 126. The dotted lines

show the excess of horn removed preparatory to shoeing.]

Among other treatments to be noted we may mention one or two to be found

chiefly in Continental works on this subject.

The method of Gross consists in thinning down with a rasp about 1-1/2

inches of the horn of the wall immediately below the coronet, the thinned

portion extending from heel to heel. The groove made is filled with

basilicon ointment,[A] and the coronet stimulated with a cantharides

ointment, In this way there is induced to grow from the coronet a new wall

of nearly normal dimensions.

[Footnote A: Basilicon ointment is made by heating together resin 8 parts,

beeswax 8 parts, olive oil 8 parts, and lard 6 parts. Allow to cool without

stirring.]

By other operators (Bayer, Imminger, Meyer, and Gunther) this treatment

has been modified by enlarging upon it and removing the whole of the

adventitious horn.

[Illustration: FIG. 128.--THE SHOE WITH HEEL-CLIP.]

This is done by means of the drawing-knife and the rasp, the ugly-looking

pumiced foot being carefully cut and trimmed until, so far as outward

appearances are concerned, it is perfectly normal. This done, the whole

foot is treated with a suitable hoof ointment, and a shoe applied that

affords protection to the sole without imposing pressure upon it. The

shoe indicated is either an ordinary shoe with an unusually broad and

well-seated web, or the seated Rocker Bar of Broad. With either it is well

to additionally protect the sole by means of a leather or rubber pad and

tar stopping, or by using the Huflederkitt described on p. 148. In every

case the nails must be kept well back in order to avoid the weakened and

degenerated horn at the toe, and to take advantage of the greater growth of

horn at the heels.

The wisdom of thus removing the whole of the adventitious horn may be

questioned. Although a foot of a nearly normal shape is obtained, it must

be remembered that the grave alterations within it are unchanged, and

that in certain positions the operation must have carried us nearer the

sensitive structures than is advisable.

All other treatments failing, the operation of neurectomy has been advised.

This we do not think wise. One would imagine that, with degenerative

processes already going on in the foot, the tendency to gelatinous

degeneration, always to be looked for in neurectomy, would be increased.

This, as a matter of fact, is the case, and is borne out by the statements

of those who have tried this method of treatment. In many cases the

lameness even is not got rid of. Even where it is, the operation is

afterwards followed by a great tendency to stumble, by sloughing of the

hoof, or by a marked increase in the adventitious horn, and a consequent

greater deformity of the foot.

Sooner than risk neurectomy, it seems to us wiser to give a trial to the

operation advocated by M.G. Joly, namely, that of ligaturing one of the

digital arteries on each affected foot. This operation is performed in the

same position as is the higher operation of plantar neurectomy, and may be

either internal or external. The vessel is exposed, and a double ligature,

preferably of silk, placed on it. The artery is then divided between

the two ligatures. The immediate effect of the operation is to cause

a considerable diminution in the arterial pressure, and so lessen the

intensity of the ostitis in the os pedis. Its consequences are not so

serious as those of neurectomy, and it decongests tissues which neurectomy

congests.

In cases related by M. Joly this operation, practised both in conjunction

with removal of the excess of horn and without it, has resulted in a marked

improvement in the gait, the animal going to work one month after the

treatment, and remaining sound for some time afterwards.

2. SEEDY-TOE.

_Definition_.--A defect in the horn of the wall, usually at the toe, but

occurring elsewhere, resulting in loss of its substance in either its

internal or external layers (see Figs. 129, 130, and 131).

_Causes_.--The most common factor in the causation of this defect is

undoubtedly disease of the sensitive laminæ. We have, in fact, just given

an excellent example of the formation of a seedy-toe in the sections of

this chapter devoted to laminitis (see pp. 265 and 286). The cavity here

formed by the outpouring of the inflammatory exudate and the separation of

the sensitive and horny laminæ persists. It becomes filled with the

dried remains of the exudate and perverted secretions from the horny and

sensitive laminæ (see p. 287). As yet, however, the cavity is closed below,

and its existence only surmised. Later, with successive visits to the

forge, the layer of solar horn forming its floor is cut away, and the

cavity exposed to view. Its mealy-looking contents are removed, and the

case reported by the smith.

Although occurring in this way with an acute attack of laminitis, it must

be remembered that seedy-toe may arise without previous noticeable cause.

The first intimation the owner has is a report from the forge that

seedy-toe is in existence. To refer to cases so arising a probable cause is

far from easy. At one time it was believed to be due to parasitic infection

of the horn. Others have blamed the pressure of the toe-clip, excessive

hammering of the wall, or pressure from nails too large or driven too

close. Others, again, say that seedy-toe may result from a prick in the

forge, from hot-fitting of the shoe, from standing on a dry and sandy soil,

or from the use of high calkins on the front shoes. In these cases--cases

with an insidious onset--we are inclined to the opinion that the disease

of the horn commences from below, and that the sensitive laminæ become

implicated later. Holding this view, one must account for the commencing

disease of the horn by giving, as causes, firstly, those factors (as,

for instance, alternate excessive dampness and dryness) leading to

disintegration of the horn tubules; secondly, the penetrating into and

between the degenerated tubules of parasitic matter from the ground; and,

thirdly, the final breaking up of the horn, and spread of the lesion under

the invasion thus started.

[Illustration: FIG. 129.--DIAGRAM ILLUSTRATING POSITION OF SEEDY-TOE

(INTERNAL). 1, The horn of the wall; 2, the horn of the sole; 3, the cavity

of the seedy-toe; 4, the os pedis; 5, the keratogenous membrane.]

_Symptoms_.--Lameness sometimes attends seedy-toe, and sometimes does not.

This is an important point to be carried in mind by the veterinary surgeon

who is accustomed in his practice to have many animals pass through his

hands for examination as to soundness. An animal with advanced seedy-toe--a

condition constituting serious unsoundness--may walk and trot absolutely

sound, and may give no indication, either in the shape of the wall or the

condition of the sole, that anything abnormal is in existence. Later,

however, after the veterinary surgeon has passed him, the purchaser lodges

the complaint that the horse has a bad seedy-toe, which, so he is told,

must have been there for some time. In this case, culpable though he may

appear, there is every excuse for the veterinary surgeon.

Once the cavity is opened at the toe in the neighbourhood of the white

line, then diagnosis is easy. A blunt piece of wood, the farrier's knife,

or a director may be easily passed into it, sometimes as far up as

the coronary cushion (see Fig. 129). Issuing from the opening is seen

occasionally a little inspissated pus; more often, however, the dry,

mealy-looking detritus to which we have before referred. This form of the

disease we may term 'Internal Seedy-Toe.' for, plainly enough, it has had

its origin in chronic inflammatory changes in the keratogenous membrane.

[Illustration: FIG. 130.--EXTERNAL SEEDY-TOE COMMENCING AT THE PLANTAR

BORDER OF THE WALL.]

[Illustration: FIG. 131.--EXTERNAL SEEDY-TOE COMMENCING ON THE ANTERIOR

FACE OF THE WALL.]

Disease of the horn and loss of its substance may, however, also commence

from without. A report on this condition, under the title of 'External

Seedy-Toe,' is to be found in vol. xxix. of the _Veterinary Journal_, from

which we borrow Figs. 130 and 131.

In Fig. 130 it will be seen that the disease commences at the plantar

surface of the toe, and extends upwards and inwards. The same condition

may also appear anywhere between the coronet and the ground, gradually

extending into the substance of the wall, as shown in Fig. 131. According

to the writer, Colonel Nunn, the progress of the disease in this latter

case appears to be faster in a downward than in an upward direction. This,

however, is more apparent than real, as the rate of growth of the horn

downwards detracts from the progress of the disease upwards, although it

spreads over the horn at the same rate.

Before concluding the symptoms, we may again allude to the fact that,

although usually occurring at the toe, the same condition may be met with

in other positions--namely, at either of the quarters. In appearance and in

other respects it is identical with that occurring at the toe.

When the animal is lame and the existence of seedy-toe is surmised, or when

the cause of the lameness is altogether obscure, a little information may

perhaps be gathered from noting the wear of the shoe. If the animal has

been going lame for any length of time as a result of disease in the

sensitive laminæ, then the shoe will be greatly thinned at the heels, and

the toe but little worn.

_Treatment_.--As with diseased structures elsewhere, the most rational

treatment, when possible, is that of excision. The entire portion of the

wall forming the anterior boundary of the cavity is thinned down with

the rasp and afterwards removed with the knife, wholly exposing the

hypertrophied, but usually soft layer of horn covering the sensitive

structures. These hypertrophied portions are also removed, and every

particle of the dust-like detritus cleaned away. After-treatment consists

in dressing the parts with a good hoof ointment, protecting them, if

necessary, with a pad of tow and a stout bandage. It may be that the

removal of a large portion of the wall may for some time throw the animal

out of work. Acting on Colonel Fred Smith's suggestion, this may be avoided

by having made a thin plate of sheet-iron, slightly larger in circumference

than the portion of horn removed, and shaped to follow the contour of the

foot. This made, it is sunk flush with the wall by hot-fitting it, and kept

in position by several small steel screws fixed into the sound horn, just

as in the treatment for sand-crack (see p. 174). This will serve the

useful purpose of maintaining in position any dressing that may be thought

necessary, of acting as a support to the horn left on each side of the

portion removed, and of keeping the exposed structures free from dirt and

grit.

Practical points to be remembered in fitting plates of this description

to the feet are: The plate must never quite reach the shoe, or it will

participate in the concussion of progression, and so loosen the screws that

hold it in place. For the same reason, that portion of the sole adjoining

the piece of horn removed must have its bearing on the shoe relieved. The

screws holding the plate should be oiled to prevent rusting, and should

take an oblique direction in order to obtain as great a hold as possible on

the wall.

When excision is deemed unwise or unnecessary, treatment should be directed

towards maintaining the cavity in a state of asepsis. To this end it

should be thoroughly cleaned of its contents, and afterwards dressed with

medicated tow. The ordinary tar and grease stopping is as suitable as any.

This, together with the tow, is tightly plugged into the opening and kept

in position by a wide-webbed shoe. Instead of the tar stopping and the tow,

there may be used with advantage the artificial hoof-horn of Defay (see p.

152). Before using this the cavity should again be thoroughly cleaned out,

and should in addition be mopped out with ether. The latter injunction is

important, as unless the grease is thus first removed, the composition will

fail to adhere to the horn. With the cavity thus cleaned and prepared, the

artificial horn, melted ready to hand, is poured into it and allowed to

set.

In every case, no matter what else the treatment, the bearing of the horn

adjacent to the lesion should be removed from the shoe.

Whether practising the method of plugging the cavity or that of excision of

the wall external to it, attempts to quickly obtain a new growth of horn

from the coronet should be made. To further that, frequent stimulant

applications should be used. Ointment of Biniodide of Mercury 1 in 8, of

Cantharides 1 in 8, or the ordinary Oil of Cantharides, either will serve.

3. KERAPHYLLOCELE.

_Definition_.--By this term is indicated an enlargement forming on the

inner surface of the wall. In shape and extent these enlargements vary.

Usually they are rounded and extend from the coronary cushion to the sole,

sometimes only as thick as an ordinary goose-quill, at other times reaching

the size of one's finger. Often they are irregular in formation and

flattened from side to side.

[Illustration: FIG. 132.--A PORTION OF THE HORN OF THE WALL AT THE TOE

REMOVED IN ORDER TO SHOW A KERAPHYLLOCELE ON ITS INNER SURFACE.]

_Causes_.--Keraphyllocele is very often a sequel to the changes occurring

at the toe in laminitis. Probably, however, the most common cause is an

injury upon, or a crack through, the wall. It may thus occur from excessive

hammering of the foot, from violent kicking against a wall or the stable

fittings, and from the injury to the coronet known as 'tread.' It may also

occur as a sequel to complicated sand-crack, and to chronic corn.

That fissures in the wall are undoubtedly a cause has been placed on record

by the late Professor Walley, who noticed the appearance of these horny

growths following upon the operation of grooving the wall.[A]

[Footnote A: _Journal of Comparative Pathology and Therapeutics_, vol. iii,

p. 170.]

This gentleman had a large Clydesdale horse under his care for a bad

sand-crack in front of the near hind-foot, and, as the lameness

was extreme, he adopted his usual method of treatment--viz., rest,

fomentations, poulticing, and the making of the V-shaped section through

the wall, and subsequently the application of an appropriate bar shoe

to the foot, and repeated blisters to the coronet. In a short time the

lameness passed off, and the horse was put to work. A few days later the

animal met with an accident, and was killed.

On examining a section of the hoof it was found that a vertical horny ridge

corresponding to the external fissure had been formed on the internal

surface of the wall, and that a well-marked cicatrix extended upwards

through the structure of the hoof at the part forming the cutigeral groove;

furthermore, _a similar ingrowth had been taking place in the line of the

oblique incisions made for the relief of the sand-crack_.

This case has an important bearing on the operation of grooving the wall,

which operation we have several times in this work advocated for the relief

of other diseases. It teaches us that the incisions should not be carried

so completely through the horn as to interfere with and irritate the

sensitive laminæ, and so set up the chronic inflammatory condition leading

to hypertrophy of the horn.

From the position on the os pedis of the indentation made in it by the

keraphyllocele (see Fig. 133) it has been argued that pressure of the

toe-clip is a cause of the new growth. This, we should say, cannot be a

very strong factor in the causation, for, while we admit that the continual

pressure of the clip, and the heavy hammering that sometimes fits it into

position, is likely to set up a chronic inflammatory condition of the

sensitive laminæ in that region, we must still point out that the rarity

of keraphyllocele, as compared with the fact that clips are on every shoe,

does not allow of the argument carrying any great weight.

_Symptoms_.--Except under certain conditions this defect is difficult

of detection. As a rule, lameness is not produced by it. In making that

statement we are led largely by the conclusion arrived at by Professor

Walley. This observer noted the fact that ingrowths of horn such as we are

describing nearly always take place in false quarter, or after a sand-crack

has been repaired, and that they commonly occur after the operation of

grooving the wall in the manner we have just shown.

Now, we know that quite often under these circumstances the horse goes

perfectly sound. Thus, while we know that in all probability keraphyllocele

is in existence, we have ocular demonstration that the animal is quite

unaffected by it.

In some cases, however, lameness is present. During the early stages of

the growth's formation it is but slight, increasing as the keraphyllocele

enlarges. Should this be the case, other symptoms present themselves.

The coronet is hot, and tender to the touch, sometimes even perceptibly

swollen, and percussion over the wail is met with flinching on the part

of the animal. In other cases one is led to suspect the condition by

the prominence of the horn of the wall of the toe. This is distinctly

ridge-like from the coronet to the ground, while on either side of it the

quarters appear to have sunk to less than their normal dimensions. We

believe this to be an illusion, as a ridge of any size at the toe readily

gives one the impression of atrophy behind it, without this latter

condition being actually present.

Should this ridge-like formation and the accompanying symptoms of pain and

lameness occur after repair of a sand-crack, then keraphyllocele may, with

tolerable certainty, be diagnosed. When these outward signs are wanting,

however, and the true nature of our case is a matter of mere conjecture, a

positive diagnosis may still be made at a later stage--that is, when the

abnormal growth of horn reaches the sole. In this case either there is

met with when paring the sole a small portion of horn, circular in form,

distinctly harder than normal, and indenting in a semicircular fashion the

front of the white line at the toe, or solution of continuity between the

tumour and the edge of the sole and the os pedis takes place, and the

lameness resulting from the ingress of dirt and grit thus allowed draws

attention to the case.

_Pathological Anatomy_.--With the sensitive structures removed from the

hoof by maceration or other means, these growths are at once apparent. They

may occur in any position, but are usually seen at the toe, and they may

extend from the coronary cushion to the sole, or they may occupy only

the lower or the upper half of the wall. In places the tumour (or 'horny

pillar' as the Germans term it) is roughened by offshoots from it, and does

not always exhibit the smooth surface depicted in Fig. 132. Commonly, the

horn composing the new growth is hard and dense. Sometimes, however, it is

soft to the knife, and is then found to be itself fistulous in character,

a distinct cavity running up its centre, from which issues a black and

offensive pus.

In a few cases the sensitive laminæ in the immediate neighbourhood are

found to be enlarged, but in the majority of cases atrophy is the condition

to be observed. Not only are the sensitive structures found to be shrunken

and absorbed, but the atrophy and absorption extends even to the bone

itself (see Fig. 133). This latter is a result of the continued pressure of

the horny growth, in a well-marked case ending in a sharply-defined groove

in the os pedis in which the keraphyllocele rests. The fact that the softer

structures, and even the bone, thus accommodate themselves to the altered

conditions is, no doubt, the reason that lameness in many of these cases is

absent.

_Treatment_.--It is doubtful whether anything satisfactory can be

recommended. When we have suspected this condition ourselves, it has been

our practice to groove the hoof on either side of the toe, after the manner

illustrated in Fig. 120, and, at the same time, point-firing the coronet

and applying a smart cantharides blister. Certainly, after this operation,

lameness has often disappeared--whether, however, as a result of the

treatment adopted or by reason of the structures within accommodating

themselves to the condition, we would not care to say.

[Illustration: FIG. 133.--OS PEDIS SHOWING THE GROOVE IN IT CAUSED BY

ATROPHY AND ABSORPTION INDUCED BY PRESSURE OF A KERAPHYLLOCELE.]

Other writers advocate the removal of that portion of the wall to which the

tumour is attached, after the manner described on p. 182, and illustrated

in Fig. 98. This, however, should be a last resource, and should be adopted

only when weighty reasons, such as excessive and otherwise incurable

lameness, appear to demand it.

4. KERATOMA.

In our nomenclature the terms 'Keratoma' and 'Keraphyllocele' are both used

to indicate the condition we have just described. There are some, however,

who reserve the term 'Keratoma' for horny tumours occurring only on the

sole, and for that reason we draw special attention to the word here.

Keratoma may thus be used to describe what we have called keraphyllocele

directly that growth makes its appearance at the sole, and is there able

to be cut with the knife. Similar hard and condensed growths may, however,

make their appearance on the sole in other positions quite removed from the

white line, plainly being secreted by the villous tissue of the sensitive

sole, and having no connection whatever with the sensitive laminæ.

They appear as circular patches, varying in size from a shilling to a

two-shilling piece. Compared with the surrounding horn, they stand out

white and glistening, while in structure they are dense and hard, and

offer a certain amount of resistance to the knife. They are of quite minor

importance, and, beyond keeping them well pared down, need no attention.

Keratoma probably offers us the best analogy we have to corn of the human

subject.

5. THRUSH.

_Definition_.--A disease of the frog characterized by a discharge from it

of a black and offensive pus, and accompanied by more or less wasting of

the organ.

_Causes_.--The primary cause of this affection is doubtless the infection

of the horn, and later the sensitive structures, with matter from the

ground. Those factors, therefore, leading to deterioration of the horn, and

so exposing it to infection, may be considered here. Such will be changes

from excessive dampness to dryness, or _vice versâ_; work upon hard and

stony roads; prolonged standing in the accumulated wet and filth of

insanitary stables, or long standing upon a bedding which, although dry, is

of unsuitable material.

In this latter connection may be mentioned the harm resulting from the use

of certain varieties of moss litter. This we find pointed out by J. Roalfe

Cox, F.R.C.V.S.[A] Tenderness in the foot was first noticed, and, on

examination, the horn of the sole and of the frog was found to be

peculiarly softened. It afforded a yielding sensation to the finger, not

unlike that which is imparted by indiarubber, and on cutting the altered

horn it was almost as easily sliced as cheese-rind. The outer surface

being in this way slightly pared off, the deeper substance of the horn was

discoloured by a pinkish stain. The horn of the frog was in many instances

found detaching from the vascular surface, which was very disposed to take

on a diseased action, somewhat allied to canker, and became extremely

difficult to treat.

[Footnote A: _Veterinary Journal_, vol. xvi., p. 243.]

Conditions such as these, although not constituting the disease itself,

certainly lay the frog open to infection, especially if afterwards the

animal is called upon to work in the mud of the streets of a large town, or

to stand in a badly drained and damp stable.

A further cause of thrush is to be found in the condition of the frog,

brought about by contraction of the heels (see p. 118). We have already

seen that one of the most prominent factors in the causation of contraction

is the removal of the frog from the ground by shoeing, with its consequent

diminution in size and deterioration in quality of horn. This leads to

fissures in the horny covering, and favours infection of the sensitive

structures beneath. Thrush is, in fact, nearly always present in the later

stages of contracted foot.

By some thrush is believed to be but the commencement of canker. With this,

however, we do not hold. We believe both to be due to specific causes as

yet undiscovered, but that the cause of thrush is not the one operating in

canker. In arriving at this conclusion we are guided by clinical evidence.

The two conditions are quite dissimilar, even in appearance, and, while

one is readily amenable to treatment, the other is just as obstinately

resistant.

_Symptoms_.--The symptoms of thrush are always very evident. Probably the

first thing that draws one's attention to it is the stench of the puriform

discharge. The foot is then picked up and the characteristic putrescent

matter found to be accumulated in the median, and often in the lateral,

lacunæ. The organ is wasted and fissured, the horn in the depths of the

lacunæ softened and easily detachable, and portions of the sensitive frog

often laid bare.

With a bad thrush lameness is present, the frog itself is tender to

pressure, and often there is considerable heat and tenderness of the heels

and the coronet immediately above. More especially is this noticeable after

a journey.

It is, perhaps, more common in the hind-feet than in the fore, and more

often met with in heavy draught animals than in nags. The hind-feet are, of

course, more open to infection by reason of their being constantly called

upon to stand in the animal discharges in the rear of stable standings,

while it is a well-known fact that heavy animals have their stables kept

far less clean, and their feet less assiduously cared for, than do animals

of a lighter type.

In a nag-horse with thrush of both fore-feet lameness becomes sometimes

very great. The gait when first moved out from the stable is feeling

and suggestive of corns, while progress on a road with loose stones is

sometimes positively dangerous to the driver.

_Treatment_.--When this condition has arisen, as it often does, from want

of counter-pressure of the frog with the ground, this pressure must be

restored after the manner described when dealing with the treatment of

contracted foot (see p. 125) either by the use of tip or bar shoes, or by

suitable pads and stopping.

So far as direct treatment of the lesion itself is concerned, the first

step is to carefully trim away all diseased horn and freely open up the

lacunæ in which the discharge has accumulated. Good results are then often

arrived at by poulticing, afterwards followed up by suitable antiseptic

dressings. With us a favourite one is the Sol. Hydrarg. Perchlor. of Tuson,

used without dilution. Others use a dry dressing, and dust with Calomel,

with a mixture of Sulphate of Copper, Sulphate of Zinc and Alum, or with

Subacetate of Copper and Tannin.

With restoration, so far as is possible, of the frog functions, and with

careful dressing, a cure is nearly always obtained.

6. CANKER.

_Definition_.--Under this unscientific, yet expressive term, is indicated a

chronic diseased condition of the keratogenous membrane, commencing always

at the frog, and slowly extending to the sole and wall, characterized by a

loss of normal function of the horn secreting cells, and the discharge of a

serous exudate in the place of normal horn.

_Causes_.--The exact cause of canker has still to be discovered. Therefore,

before expressing an opinion as to what the _probable_ cause may be, we may

state here that such opinion can only be based upon clinical observation.

Such being the case, we are almost duty bound to give the views of older

authors before those of more modern writers.

From the mass of material ready to hand we may select the following as

serving our purpose.

The earliest opinion appears to have been that canker, as the name

indicates, was of a cancerous or cancroid nature. This was also believed by

Hurtrel D'Arboval, who looked upon canker as carcinoma of the recticular

structure of the foot. The same theory we find enunciated in the

_Veterinary Journal_ so late as 1890. Although the word 'cancer' or

'carcinoma' is not there used, the author employs the terms 'Papilloma' and

'Epithelioma' with the evident intention of expressing his belief in the

malignant nature of the disease.

Another early opinion was that the disease was a _spreading ulcer_,

gradually extending and changing the tissues which it invaded.

A further early theory, and one which if not still believed in, has died a

hard death, is the constitutional theory. This was believed in by nearly

all the older writers, and is mentioned so late as 1872 by the late

Professor Williams. In his 'Principles and Practice of Veterinary Surgery,'

he says: 'Canker is a constitutional disease due to a cachexia or habit

of body, grossness of constitution, and lymphatic temperament.' This, we

believe, is credited to-day by some, and yet, quite 100 years before the

date of the 1872 edition of Williams's work--in 1756, to be exact--we find

a veterinary writer when talking of grease (a disease, by-the-by, very

closely allied to canker) exclaiming against this habit of referring

everything which we do not rightly understand to some ill-humour of the

body. The wisdom his words contain justifies us in giving them mention

here. 'It is a very foolish and absurd Notion,' he says, 'to imagine a

Horse full of Humours when he happens to be troubled with the Grease. But

such Shallow Reasoning will always abound while Peoples' Judgments are

always superficial. Therefore, to convince such unthinking Folks, let them

take a thick Stick and beat a Horse soundly upon his Legs so that they

bruise them in several Places, after which they will swell, I dare say,

and yet be in no danger of Greasing. Now, pray, what were these offending

Humours doing before the Bruises given by the Stick?'

At the present day it is safe to assert that neither the ulcerative, the

cancerous, nor the constitutional theory is believed in widely, and, among

the mass of contrary opinions as to the cause of this disease, we may find

that even quite early many of the older writers had discarded them.

Quoting from Zundel, we may say that Dupuy in 1827 considered canker as

a hypertrophy of the fibres of the hoof, admitting at the same time that

these fibres were softened by an altered secretion; while Mercier in 1841

stated that canker was nothing more than a chronic inflammation of the

reticular tissue of the foot, characterized by diseased secretions of this

apparatus.

Saving that they make no mention of a likely specific cause, these last two

statements express all that we believe to-day. As early as 1851, however,

the existence of a specific cause was hinted at by Blaine in his

'Veterinary Art.' We find him here describing canker as a _fungoid_

excrescence, exuding a thin and offensive discharge, which _inoculates_ the

soft parts within its reach, particularly the sensitive frog and sole, and

destroys their connections with the horny covering.

The use of the word 'fungoid,' and particularly that of 'inoculate,' is

suggestive enough, and is evidence sufficient that either Blaine or his

editor recognised, simply through clinical observation, the working of a

special cause.

Four years later, Bouley is found holding the opinion that canker was

closely allied to tetter, thus recognising for it a local specific cause.

The same observer also pointed out that the secretion of the keratogenous

membrane instead of being suspended was greatly increased, taking care to

explain, as did Dupuy, that the products of the secretion were perverted

and had lost their normal ability to become transformed into compact horn.

In 1864 this slowly growing recognition of a specific cause received

further impetus from the statements of Megnier. This observer claimed to

have discovered in the cankerous secretions the existence of a vegetable

parasite (namely, a cryptogam, as in favus), which he termed the

keraphyton, or parasitic plant of the horn.

Modern research, though failing to substitute anything more definite, has

not confirmed this. The exact and exciting cause of canker is therefore

still an open question, and a matter for research. We may, however, sum the

matter up by briefly discussing the causes, so far as clinical observation

teaches us. This we shall do under two headings--namely, _Predisposing_ and

_Exciting_.

_Predisposing Causes_.--Starting with the assumption that the disease is

due to local infection, we may relate as predisposing causes anything

having a prejudicial effect upon the horn, disintegrating it, and so laying

the tissues beneath open to attack. The most prominent in this connection

is certainly a continued dampness of the material on which the animal

has to stand. Particularly is this the case when the material is also

excessively foul and dirty, contaminated with the animal discharges, and

presumably swarming with the lower forms of animal and plant life. We

shall therefore find bad cases of canker in stables where the "sets" are

irregular, or where no paving at all is attempted, where the drainage

is defective, and where darkness and want of proper ventilation favours

organismal growth. The fact that with modern drainage and a general

hygienic improvement in stabling, canker has to a large extent died out,

supports this contention.

Again, as with thrush, anything removing the counter-pressure of the frog

with the ground and throwing that organ out of play, may be looked upon

as a predisposing cause. The atrophy of the frog thus occurring, the

deterioration in the quality of its horn and the fissures in its surface

lay it specially open to infection. That one of the principal factors in

the treatment of canker is a restoration of ground-pressure to the frog and

the sole is sufficient proof of this.

Further, it is well to note that, although playing no part in the actual

causation, certain constitutional conditions may in some measure predispose

the foot to attack. Clinical observation teaches us that animals of a

lymphatic nature, with thick skins and an abundance of hair, with flat feet

and thick, fleshy frogs, are far more liable to attack than are animals

with reverse points.

_Exciting Causes_. Those who give this subject careful consideration cannot

fail to arrive at the conclusion that canker is most certainly due to local

infection with a specific poison, and that poison a germicidal one from the

ground. The symptoms arising may be due to the action of a single germ, or

to two or more germs acting in conjunction. As to whether the parasitic

invasion is single or multiple we cannot feel certain, but that it _is_

parasitic we feel absolutely assured.

It is simply the light that bacteriological advance has made during the

last two decades that enables us to make the statement with such feelings

of assurance. We arrive at our conclusions by reasoning from analogy.

Here we have a disease always exhibiting the same symptoms, more or less

peculiar to one class of animal, always with a similar characteristic

appearance and smell, always obstinately refractory to treatment, showing

always a tendency to spread to the other feet of the same animal, and often

to the feet of other animals _near enough to become_ infected, and always

cured--when cured it is--by a treatment which may be summed up in two words

as 'rigid antisepsis.' Other diseases, with points in common with this,

have been directly proved to be due to a specific cause. Common regard for

logic compels us to admit the same for canker.

[Illustration: FIG. 134.--A FOOT, THE SUBJECT OF CANKER, SHOWING

DESTRUCTION OF THE HORNY FROG, AND A FUNGOID-LOOKING HYPERTROPHY OF THE

TISSUES BENEATH.]

_Symptoms and Pathological Anatomy_.--The symptoms of canker are seldom

noticeable at the commencement of an attack. The disease is slow in its

progress; for some time confines its ravages to the sub-horny tissues

unseen, and is quite unattended with pain. It is not observed, therefore,

until considerable damage has been done, and the disease is far advanced.

What is usually first seen is a peculiar softening and raising of the horn

of the frog. The infective material has set up a chronic inflammation of

the keratogenous membrane, leading to abnormal secretion, and, in place of

the horny cells it should normally secrete, is thrown out an abundance of a

serous fluid.

This upraised and softened horn once thrown off is not again renewed, and

the whole of the sensitive frog and perhaps a portion of the sensitive sole

is left uncovered. In place of the normal horn, however, is often found a

hypertrophy of the elements of the keratogenous membrane leading to huge

fungoid-looking growths with a papillomatous aspect, damp in appearance and

offensive in smell, and readily bleeding when injured (see Fig. 131).

The horn immediately surrounding the lesion is loose and non-adherent to

the sensitive structures. This indicates, of course, that the disease has

spread further beneath the horny covering than is at first sight apparent.

Portions of this loose horn removed reveal beneath it a caseous foetid

matter, easily removed by scraping (the perverted secretion of the

keratogenous membrane). When this is carefully scraped away, the sensitive

structures appear to be covered with a thin, smooth membrane, gray in

colour and almost transparent, while beneath it may be seen the red

appearance of normal sensitive structures.

If the horn surrounding the lesion is not touched with the knife, but

little is seen of the extent of the disease, for that removed by natural

means is often very small in quantity. To all intents and purposes the

disease appears to be confined to the frog. This appearance is misleading,

especially if the disease has been in existence for some time, for it

may have easily spread to the whole of the sole, and even to the greater

portions of the laminæ secreting the wall.

It is, in fact, not until the pressure exerted by the normal horn

is removed by its breaking away that the vascular structures of the

keratogenous membrane begin to swell, and the perverted secretions to

enlarge in size. Once the pressure is removed, however, this quickly

comes about, and the characteristic fungoid growths rapidly make their

appearance.

This tendency to spread is highly indicative of canker. The serous matter

exuding from the diseased keratogenous membrane appears, in fact, to be

highly infective. Once its flow is commenced, it slowly, but surely,

invades the sensitive structures near it, appearing, as Elaine has put it,

to 'inoculate' them. What is really the case, of course, is not that the

discharge itself is infective, but that it is contaminated with infective

material.

The fungoid-looking growths to which we have before referred are, in

reality, nothing more than the villi of the sensitive frog and sole greatly

hypertrophied and irregular in shape. At times the hypertrophy is as a huge

and compact enlargement occupying the position of the frog. Sometimes,

however, it occurs as numerous elongated and twisted fibrous bundles,

separated from each other by deep clefts, and the clefts filled with the

offensive cankerous discharge (see Fig. 134).

[Illustration: FIG. 135.--LOWER ASPECT OF CANKERED FOOT, SHOWING

DESTRUCTION OF WALL.]

At a very advanced stage canker leads to destruction of much of the horny

sole and frog; or even parts of the wall may become separated from the

tissues beneath, and break away from the foot (see Fig. 135). At other

times the disease brings about a deformity of the whole of the foot. Its

longitudinal and transverse diameters become enormously increased, and the

whole foot apparently flattened from above to below (see Fig. 136). This

indicates that not only has the horny sole been entirely destroyed, but

that the destructive process has also extended to the greater part of the

lower half of the wall, with a consequent hypertrophy of exposed soft

structures, and a sinking of the bony column, similar to that which occurs

in laminitis, but not so pronounced.

[Illustration: FIG. 136.--FOOT WITH ADVANCED CANKER.]

A further aspect of the badly-cankered foot is to be found in an apparently

enormous increase in the length of the wall. This we have seen protruding

for quite 5 inches beyond the plane of the sole. It simply indicates that,

in order to keep the animal at work, the smith has at every shoeing spared

the wall, so that the diseased structures might be kept from contact with

the ground.

As we have said before, pain and other symptoms of distress are quite

absent. Animals affected with canker for a long time maintain their

condition, feed well, and are quite capable of performing work under

ordinary conditions.

_Differential Diagnosis and Prognosis_.--Perhaps the only disease with

which canker may be confounded is thrush. They should, however, be easily

distinguishable. The discharge from thrush is not so profuse, and is

thicker and darker in colour, while the loosening of the horn is almost

entirely absent. Furthermore, thrush shows no tendency to spread, and, even

when left untreated, may remain confined to the frog for months, and even

years. Canker, on the other hand, is slowly progressive, and soon shows the

characteristic fungoid excresences, which growths are in thrush never seen.

A further point of difference is discovered when treatment is commenced.

Canker is found to be refractory to a point that is absolutely

disheartening, while thrush, with careful attention, is soon got under

hand, and a permanent cure effected.

The prognosis must be guarded. By many canker has been said to be

incurable. This, however, has been clearly shown to be wrong. When the

animal is young, and treatment may reasonably be judged to be economical,

then a favourable prognosis may be indulged in, provided the veterinary

surgeon intends to put into that treatment a more than ordinary amount of

individual care and attendance. Even then, however, he will have to be very

largely guided by the condition of his case. He should see that it is

not too far advanced, and that a great deformity of the hoof, or actual

exploration, does not indicate disease of the greater part of the wall.

_Treatment_.--From what has gone before, it will be seen that the

eradication of canker is no easy task, that it is, in fact, a most

difficult matter, and one not to be lightly undertaken. At the risk of

recapitulating what we have said before, we may mention here the two points

which the veterinarian must bear in mind. (1) That there is no actual

disease or alteration in structure of the deep layers of the keratogenous

apparatus. It is only the superficial, or horn-secreting, layer that

concerns us. (2) That the disease of this superficial layer is infection

with a material that may reasonably be presumed to be infective.

Put thus, treatment of canker would at first sight appear to be easy. One

would imagine that a simple and long-continued soaking of the entire foot

in a strong enough antiseptic would be all that was needed. Clinical

observation, however, shows that this is not so, and for this there must be

reasons.

The reasons are these: (1) Between us and the diseased layer upon which our

attention must be directed is often a layer of normal horn, effectually

protecting the tissues beneath from any dressing which we might consider

beneficial. (2) Anything applied with the object of destroying septic

material, but strong enough, or caustic enough, to injure the membrane upon

which we are working, only makes the case worse. The superficial layer of

the keratogenous membrane in which we have judged the disease to exist is,

after all, but a delicate structure. When attacked by the application of

too potent a drug its horn-secreting layer is easily destroyed, and thus,

although we may succeed in establishing asepsis, we cannot expect at the

point of injury a growth of horn. In its place we are confronted with large

outgrowths of inflammatory fibrous tissue. (3) Shedding of the diseased

horn and removal of the pressure exerted by the hoof faces us with

hypertrophy of the exposed villi. The difficulty of meeting this with an

adequate and evenly-distributed pressure is well enough known, and we find

in that a further reason that the treatment of canker is superlatively

difficult. (4) The material on which the animal has to stand is a distinct

bar to the maintaining of a strict asepsis.

When we have said this, it is easy to understand that canker is not to be

successfully met with any so-called specific--that it makes but little

difference what the application may be so long as it is antiseptic, and is

used by a man thoroughly conversant with the difficulties he has to contend

with, and with his mind firmly set upon surmounting them.

With this point established, we will not devote more of our space to a

consideration of the various dressings that have at different times been

highly advocated in the treatment of the disease. It is interesting,

however, to note that intensely irritating and caustic applications have

been greatly in favour. Nitric acid, sulphuric acid (either alone or its

action reduced by the addition of alcohol, oil, or turpentine), arsenic,

butter of antimony, creasote, chromic acid, carbolic acid, arsenite of

soda, and the actual cautery, have all been used.

Without dwelling further on that, we may say at once that a correct

treatment consists in (1) the removal of all horn overlying infected

portions of the keratogenous membrane, (2) the application of an antiseptic

not too powerfully caustic in its action, (3) frequent changes of the

dressings in order to insure a maintenance of antisepsis, and (4) the

application of an adequate pressure to the exposed soft structures. Thus

combated, canker is curable.

The man who, at the expense of much time and trouble, has demonstrated the

truth of these axioms is Mr. Malcolm, of Birmingham. The determination with

which he clung to his point that canker was, with correct treatment, in

every case curable, was some years ago provocative of much discussion in

veterinary circles. That he was successful in proving his contention is

more to our point here. It is his method of treatment, therefore, that we

shall give, and this we shall do by liberal extracts from Mr. Malcolm's own

writings.

'On the first occasion of operating upon and dressing the cankered foot,

it is usually necessary to cast the horse, and this may have to be done

at intervals for a second or even third time; but in most cases once is

sufficient, subsequent dressing being usually accomplished without much

difficulty, frequently even without the aid of a twitch. After the horse

has been secured, the drawing-knife is first employed; and if the frog

alone is affected, it is unnecessary even to pare the sole, the removal of

all frog horn not intimately adherent to its secreting surface being all

that is required. But if both sole and frog be involved, the whole of the

sound horn should be first thinned until it springs under the thumb,

and then, using a sharp knife, every particle of diseased horn must be

carefully removed from both sole and frog, a process much more easily, and

with far greater certainty, secured by the previous thinning of the horn.

'The removal of diseased horn should always commence at the most dependent

part of the foot, so that any hæmorrhage produced may be below the parts

still to be operated on, a matter of considerable moment for effective

treatment. But with due care there will be little hæmorrhage, as, except in

the initial stage, there is no real union between the diseased horn and the

diseased vascular secreting surface.

'After all apparently diseased horn has been removed by the knife, any

still remaining should be at once destroyed by the actual cautery, by

which it can be identified. All the diseased secreting surface should be

_carefully scraped with a thin hot iron_,[A] fungoid growths excised and

cauterized, and, indeed, every particle of cankered tissue should, if

possible, be eradicated. In securing this more reliance can be placed on

the actual cautery than on any other, whether liquid or solid: it is more

under control in application, more decisive in effect, and its results can

be anticipated with a far greater certainty. Moreover, its aid in diagnosis

is of immense value; applied to the thinned horn or secreting surface it

unmistakably demonstrates the presence or absence of canker. Healthy tissue

chars black; cankered tissue, on the contrary, bubbles up white under the

hot iron, and presents an appearance not unlike roasted cheese.

'Although this test is certain for horn thinned to the quick, it is not to

be relied upon with thick horn, the outside of which may be practically

healthy and char black, while its underlying surface may be cankered. With

this exception the test is an infallible one, as by it the demarcation

between cankered and healthy tissue can be clearly traced, and as a result

we can with equal confidence radically _remove_[A] all cankered tissue, and

conserve all healthy. As the object of that abominably cruel and barbarous

operation of stripping the sole is the exposure of all canker, and as this

can be done with equal certainty with the aid of the hot iron, there can be

no necessity for performing it. The pain of cauterizing cankered tissue,

which is a necessary operation, is infinitesimal (canker largely destroying

sensation), compared with the pain produced in the totally unnecessary

process of tearing healthy horn from a highly sensitive tissue.

[Footnote A: The words in italics are alterations in the original article

made by Mr. Malcolm in a private letter to the author (H.C.K.).]

'Having by means of the knife and cautery removed every known particle of

disease, the next procedure is to pack the surface of the sole and frog

thus exposed with a _mild dressing, such as vaseline; but if the cankered

surface has not been efficiently, scraped, than there is required a more_

[A] powerful astringent or caustic dressing, which may vary considerably

according to the individual fancy. A great favourite of mine consists of

equal parts of sulphates of copper, iron, and zinc, mixed with strong

carbolic acid, a very little vaseline being added to give the mass

cohesion. The dressing, covered by a pledget of tow, is held in position

by a shoe with an iron or leather sole, and the dressing and tow together

should be of sufficient bulk to produce slight pressure on the sole when

the nails of the shoe are drawn up. This insures contact between the

dressing and the exposed surface, as well as any benefit derivable from

pressure.

[Footnote A: The words in italics are alterations in the original article

made by Mr. Malcolm in a private letter to the author (H.C.E.).]

'The dressing of the foot and nailing of the shoe can usually be more

expeditiously performed when the horse is on his feet than when prone. If

only the frog, or the frog and a small part of the sole, be involved, the

horse should be kept at work, but if a large part or the whole of the sole

a few days' rest may be necessary; but as soon as the condition of the foot

will allow, work should be resumed, and it is simply marvellous how sound a

horse will walk while minus the greater part of his sole from canker.

'On the second day following the shoe should be removed, and the foot

redressed. To effect this it is necessary to recast the horse. Commencing

at the edge of the sound horn, at the most dependent part of the foot,

all new horn, no matter what its condition, must be pared to the quick,

especial care being taken to effectually remove any lingering disease. Want

of success is frequently attributable to neglect of this precaution.

A small particle of canker remains undetected, forms a new centre of

infection, and just when success is anticipated, much to your chagrin you

have to deal with a fresh outbreak of canker, instead of a rapidly-healing

foot. Parenthetically, I may here remark that the amount of more or less

imperfect new horn produced by a cankered surface after an effective but

not too destructive cauterization is almost incredible, and one cannot fail

to be struck with the very active proliferation here compared with the

meagre production of new horn by the healthy surface.

'After all disease has been excised, carefully clean the foot with waste,

thoroughly protect any raw surface resulting from overcauterization by some

mild agent, such as a saturated calomel ointment, reapply an astringent

dressing over the whole affected surface, and nail on the shoe. This method

of procedure should now be thoroughly carried out daily for a time, and

as it is proceeded with a successful issue soon becomes assured in nearly

every case. Where, in spite of these efforts, the disease still persists,

depend upon it the fault is with the operator, who has failed to eradicate

some centre of infection. Under these circumstances it may be necessary

to recast the patient, repare the foot, and by the aid of eye, knife,

and cautery, endeavour to find the cause, and having found it, which can

invariably be done, remove it. The usual treatment will then speedily

become successful. As the case proceeds dressing every other day will

soon be sufficient, then twice a week, and finally, once a week until

sufficiently cured.

'During this healing process, and after the complete eradication of canker

it may be again repeated, no agent seems to have a more beneficial effect

than calomel, and for this purpose it is best used as a dry powder. Under

this dressing any remaining spot of canker is readily detected by the wet

condition of the calomel when the shoe is removed the next day. In dealing

with such a spot, a very good plan, after all apparently diseased tissue

has been excised, is to touch the cankered part with solid nitrate of

silver, or a feather dipped in one of the strong mineral acids, and

then reapply calomel over the surface. The result of this treatment is

frequently very gratifying.

'In successful treatment the shoe must be removed each time--an adjustable

plate will not do, as no man can thoroughly pare and examine a foot with

the shoe on, and imperfect dressings are worse than useless. Indeed, it is

better not to pare or thin the horn at all, than to imperfectly pare, since

canker, if undestroyed, develops far more rapidly under thin horn than

under thick.

'In conclusion, I would again urge the necessity, at the very first

operation, when the horse is down, of removing _every single particle_ of

the diseased tissue, either by excision or effectual cauterization, but at

the same time taking very great care to guard against the latter being

too destructive. The cautery should be laid aside as soon as the tissue

cauterized ceases to _burn white_. The moment at which the canker has

thus been eradicated without destroying sound tissue is indicated by

the appearance of healthy horn, by the intimate union of that with the

secreting surface, and by the healthy aspect of the exuded blood when

paring has been carried to the quick.

'Should subjacent healthy structures be destroyed during the process,

that is shown by the production of a raw sore, or of a sore to which a

"sit-fast," coextensive to the injury, is firmly attached. This seriously

retards recovery. The secreting surface having been destroyed, no new horn

can be produced directly from the part, and a new secreting surface and new

horn have now to grow inwards from the surrounding undestroyed tissue, and

that is a slow process. At the same time, on the principle of choosing

the least of two evils, practical experience teaches that it is better to

produce a small sore or a "sit-fast" than to leave a part of the canker

undetected; but, on the other hand, it is better to leave a small part

of canker undetected, which can be recognised and removed at the next

examination, than to cause a large slough. The object of the skilful

surgeon is, naturally, to avoid both extremes; and if trouble be taken to

carry out the procedure described, there need be no fear of the result.'[A]

[Footnote A: _Journal of Comparative Pathology and Therapeutics_, vol. iv.,

p. 24.]

Treated in this way, the horse with cankered feet may be usually kept at

work during the whole time that treatment is carried out, and a cure is

obtainable in periods varying from six weeks to six or even twelve months.

The same essentials in treatment--namely, removal of diseased horn,

antiseptic dressings, and pressure--are insisted on by other writers.

Bermbach,[A] in 1888, treats canker as follows: The horse having been cast,

the undermined hoof-horn is removed with the knife, and the hypertrophied

sensitive structures, if necessary, reduced in the same manner. The chief

difficulty in removing the latter is experienced in the lateral lacunæ of

the frog, where it is most conveniently scraped away with a spoon or sharp

curette. Professors Hoffmann and Imminger also operate in the same way,

applying an Esmarch's hæmostatic bandage, and using the knife and curette

freely.[B]

[Footnote A: _Ibid_., vol. ii., p. 68.]

[Footnote B: _Veterinary Journal_, vol. xxxv., p. 433.]

Hæmorrhage is afterwards arrested, and a dressing of perchloride of mercury

(a solution, 1/2 per cent., in equal parts of alcohol and water) applied.

The after-dressings succeeding best are those of _slightly_ caustic and

astringent agents, preferably in the form of a powder, and held in position

by carbol-jute pads and linen bandages applied with a certain amount of

pressure.

The same author draws attention to the fact that caustic agents such as

nitrate of lead, chloride of zinc, etc., act too powerfully if the bleeding

has been arrested and the wound disinfected. They then form a thick crust,

under which profuse suppuration takes place. The same agents are likewise

contra-indicated when hæmorrhage is still present. In this latter case

they combine with the blood to form metallic albuminates, which lie as an

impenetrable layer on the surface of the wound, and so hinder the action of

drugs on the tissue below.

During his after-treatment, Bermbach advocates removal of the dressings

every second day, all cheesy material to be scraped away with the knife,

and the sublimate lotion to be used again. He also insists on the animal

being kept standing in a _dry stable_,--nothing but a stone pavement kept

clean--and put to regular work in a plate shoe after the first or second

week. Cure of advanced cases is said to be obtainable in from four to six

weeks.

As illustrative of the value of pressure in the treatment of canker, we may

also draw attention to a treatment advocated by Lieutenant Rose.[A] This

observer holds that adequate pressure is unobtainable by packing the foot,

and, to obtain it, removes the wall from heel to heel, much after the

manner of preparing the foot for the Charlier shoe, so that the _whole_ of

the weight is taken by the sole and the frog. Tar and tow is then lightly

applied, the foot placed in a boot, and the patient turned into a

loose-box. The dressing is repeated at intervals of four or five days until

the animal is cured.

[Footnote A: _Veterinary Record_, vol. xi., p. 435.]

Those who have followed this method of treatment have modified it by

actually shoeing the animal Charlier fashion, and keeping him at work,

attention, of course, being at the same time given to a proper antiseptic

dressing.

_Reported Cases_.--1. (Malcolm's Treatment[A]). The subject was a five-year

old horse belonging to a client of Mr. Giver's, of Tamworth. The case was

an exceptionally bad one, for not only was the whole of the frog and sole

of the near hind-foot cankered, but the disease on the outside quarter

extended to within 1/2 inch of the coronet, and on the inside quarter to

within 2 inches of it. As the owner, a farmer, had not proper convenience

for Mr. Olver to treat the case, the latter asked me, while visiting him,

if I would care to undertake the treatment, saying at the time it would

be a very good test-case, as the disease was so far advanced. I readily

agreed, and, after the necessary arrangements, had the horse removed to

Birmingham on July 2. In this case it was found necessary to cast the

animal and cauterize the foot a second time before a healthy granulating

surface was secured; but after this the progress towards recovery was

uninterrupted, although necessarily slow, on account of the large amount of

new secreting surface which had to be formed.

[Footnote A: _Journal of Comparative Pathology and Therapeutics_, vol. v.,

p. 48.]

The horse was finally discharged, after inspection by Mr. Olver, absolutely

cured and free from canker, on January 7.

The illustration (Fig. 135, p. 312) is from a photograph, and it gives a

somewhat imperfect representation of the state of the foot two months after

it came under my care.

2. (Rose's Treatment.[A]) This was a bad case of canker, which had been for

two or three months treated in the ordinary manner, with but little sign

of ultimate success. Commenced in June and carried on until the end of

September, the ordinary treatment consisted in burning down the fungus

growth with the hot iron, and dressing with copper sulphate, zinc sulphate,

and boracic acid. The cauterization was repeated every five days.

[Footnote A: _Veterinary Record_, vol. xi., p. 435.]

The treatment of Lieutenant Rose was commenced at about the end of

September, at which date the disease extended from the toe on one side of

the foot right back to the heel, involving the sole, half of the frog, and

the bulb of the heel. One week after treatment the diseased surface was

drier, and granulations were more healthy. At the expiration of a fortnight

the new horn had commenced to grow from the wall, and also from the frog,

right round the diseased surface, the diseased part of the bulb of the heel

being divided from the sole by new horn.

Three to four weeks later the diseased surface was gradually getting

smaller, while in about six weeks it was quite healed up, the last place to

heal being a strip outside the bar, between it and the wall, and a smaller

spot on the bulb of the heel. These healed up simultaneously, and left the

animal sound.

3. (Treatment by Pressure, H. Leeney [A]). I was consulted in the early

part of last summer, before the dry weather had begun, as to a farm-horse

with canker in three feet. Her shoes were in the 'disgruntle' condition we

so often find on farms, that, to give her a level bearing until I should

call another day with a farrier to help me to pack the foot up in the

old-fashioned way, I had the remaining shoes pulled off. The case somehow

dropped out of my list, and I neglected to call, until asked one day to see

something else.

[Footnote A: _Veterinary Records_, vol. xi., p. 447]

I then found that, under a pressure of work, the animal had been used in

the shafts of a farm-cart on tolerably level ground, and when the dry

weather had already set in. There was a distinct improvement in all the

diseased feet, and as she was badly wanted I contented myself with rasping

off some broken crust, and supplied some caustic dressing for use at night.

Without shoes she worked continuously on the dry and hard meadow-land for

several weeks, and was practically cured in something less than three

months. My astringent or caustic lotion may have had something to do with

the cure of the deep-seated parts, but the bare recital of the case should

be sufficient to show that it is all a question of bearing, or nearly so.

7. SPECIFIC CORONITIS.

_Definition_.--In describing this condition under the above heading, we

are following the lead of Mr. Malcolm. We may define it as a chronic

inflammatory condition of the keratogenous membrane, usually confined to

that of the coronary cushion, the ergots and the chestnuts, but sometimes

extending to that of the frog and the sole, characterized by a malsecretion

of the affected membrane similar to that observed in canker.

_Causes_.--The cause which we have indicated for canker--namely, a local

specific one, is in all probability the one operating here. Apparently

there is a variance of opinion as to whether the condition is actually

canker or not. We think, however, that the character of the secretion of

the affected membranes, the appearance of the growths, the manner in which

they react to the hot iron, the comparative absence of pain, and other

points of similarity, point to the fact that the two conditions are

actually identical. In other words, the cause is precisely the same, and

the only point of difference is the alteration in the point of attack.

_Symptoms_.--Like canker, the disease is insidious in onset. In precisely

similar manner the horn, and in this case the skin of the coronet, is

underrun. Later there is the partial shedding and fissuring of the

undermined horn and the exuding of the characteristic discharge--in this

case not so watery as that of canker. The caseous material of canker is

also present, as is a disposition to hypertrophy of the exposed sensitive

structures. What horn is left becomes rough and irregularly fissured, and

has been likened by some observers to deeply-wrinkled bark of an old tree.

A peculiar characteristic of this condition is the state of the ergots and

chestnuts. Here the keratogenous membrane participates in the diseased

process, and their horn becomes dry and brittle, and readily splits into

small fibrous bundles very similar to the fibroid growth described in

canker. These excrescences are easily separated from the sensitive

structures beneath, and the exposed surface is seen to be more or less

moist, or even exhibiting a slight oozing of blood.

Again, as in canker, the deeper layers of the sensitive structures appear

to be normal, the horn-secreting layers being the only ones affected.

According to Malcolm, the disease is in its nature equally as inveterate as

canker, but it is easier to treat, on account of its more exposed position.

_Treatment_.--This is exactly that as described for canker.

[Illustration: FIG. 137.--SPECIFIC CORONITIS OF ALL FOUR FEET.]

[Illustration: FIG. 138.--OFF FORE-FOOT AFFECTED WITH SPECIFIC CORONITIS.]

_Recorded Case_.--The subject of this case was a young black cart gelding.

The disease is reported as having begun as thrush, and then extended to the

coronet. When I saw him he had been in a similar condition to that depicted

in Fig. 137 for, it was said, two or three months, the driver of the horse

meanwhile endeavouring to effect a cure by some potent drug of his own. The

animal was in good condition, but walked with difficulty owing to the pain.

The coronary bands were swollen to two or three times their natural size,

and this caused the hair immediately above to curl upwards. Just below the

coronary bands there was a line of separation between them and the wall.

They themselves were covered with the cheesy substance typical of canker,

and they bled on friction. Down the wall of the off fore-foot some blood

had trickled, which may be seen in Fig. 138. The frogs of all four feet

bulged backwards, and were badly affected. The soles were covered with

normal horn, but I did not resort to paring to see if they were affected.

One very curious feature about the case was the fact that all the

callosities (ergots and chestnuts) seemed to participate in the morbid

process, and they, too, were covered with a thin layer of soft cheesy horn.

The animal used to bite at his coronets and also the callosities above the

knees and hocks until they bled, which they did quite easily. The owner

would not go to the expense of having him treated, so he was destroyed.[A]

[Footnote A: Henry Taylor, _Veterinary Record_, vol. xvii., p. 311.]

CHAPTER X

DISEASES OF THE LATERAL CARTILAGES

A. WOUNDS OF THE CARTILAGES.

To a consideration of this we shall devote but little space. It is

sufficient to say that any wound in the region of the coronet should always

be given the most careful attention. More particularly should this be so

when it is ascertained that the wound has involved one of the lateral

cartilages. Wounds of non-vascular bodies such as these are always slow to

heal, and, by reason of their slowness, invite septic infection. In many

cases, in fact, it happens that they do not heal at all. Instead, the

injured part becomes necrotic, is unable to cast itself off, and remains as

a centre of infection in the depths of the wound, thus constituting what is

known as a quittor.

Apart from this, it will be remembered that the internal face of the

cartilage is in intimate contact with the pedal articulation, especially

anteriorly. Wounds in this situation are, therefore, likely to penetrate

the joint, giving us as a complication of the injury the conditions of

synovitis and arthritis.

Immediately a wound is inflicted in this position, attempts should be made

to insure thorough asepsis of the part. When possible, by far the better

way of accomplishing this will be to wholly immerse the foot in a tub of

cold antiseptic solution, and keep it there for an hour three times daily.

During the time the foot is out of the solution the wound should be

protected with a pad of carbolized tow or other suitable dressing, and

wrapped in a linen bandage or clean bag. If unable to use the bath, then

antiseptic solutions of more than moderate strength should be freely

applied to the wound and the adjacent parts, a carbolized or other

antiseptic pad placed over it, and the bandage adjusted as before. Repeated

injuries to the cartilages, even if not attended with an actual wound,

are apt to bring about their ossification and end in the formation of

side-bones.

B. QUITTOR.

_Definition_.--A fistulous wound of the foot, usually opening at the

coronet, and variously complicated according to the structures invaded by

its contained pus. For the reason that quittor is in every-day veterinary

nomenclature _usually_ associated with necrosis or other abnormal condition

of the lateral cartilage, we include its description in this chapter.

_Classification_.--It has been customary with Continental authors to

classify quittor according to the extent and position of the diseased

process. There were thus distinguished:

_(a)_ The _Simple_ or _Cutaneous Quittor_, in which had occurred nothing

more than necrosis of a portion of the coronary skin and the structures

immediately underlying it--that is, the superficial portion of the coronary

cushion.

_(b)_ The _Tendinous Quittor_, in which not only the immediately

subcutaneous tissues were attacked, but also portions of tendon and of

ligament.

_(c)_ The _Sub-horny Quittor_, in which the diseased process had invaded

the deeper portions of the coronary cushion, and continued a downward

course until the laminal tissue below the upper margin of the wall was

involved, or any other case, no matter what the starting-point, in which

pus existed within the horny box and was discharging itself by a fistulous

opening.

_(d)_ The _Cartilaginous Quittor_, in which a portion of the lateral

cartilage had become attacked and rendered necrotic.

We believe that--in this country, at any rate--the word 'quittor' is

usually held to indicate one or other of the two latter conditions, and

probably the last of these; and that the two first are held of small

account, or hardly of sufficient gravity to allow of the word 'quittor'

being applied to them. In fact, by defining quittor as a 'fistula,' or

little pipe, we have ourselves already indirectly restricted the use of the

word to the two latter conditions, for in those varieties known as Simple

or Cutaneous and Tendinous, the wound is generally broad and open, or,

at any rate, superficial, and can scarcely be strictly described as

'fistulous.' In the two latter, however, a true fistula exists. These,

however, have only one essential difference, and that consists simply in

the position of the lesion and the structures it has attacked. In the main

the symptoms will be the same, the disease in each case about equally

serious, and in each the same essentials of treatment will have to be

regarded.

In our opinion, therefore, a lengthy classification serves no useful end,

and we think matters will be simplified by considering quittor under

two headings only--namely, 'Simple or Cutaneous' and 'Sub-horny,' and

discussing the other varieties as simply complications of either of these

two.

1. SIMPLE OR CUTANEOUS QUITTOR.

_Definition_.--This condition is simply a sloughing of a portion of the

skin of the coronet, together with a portion of the immediately underlying

soft structures.

_Causes_.--This form of quittor has its origin more often than not in

contusions, punctures, or wounds of the region severe enough to cause death

of a small portion of the tissues. In this case the low vitality of the

parts does not allow of the dead portion being removed piecemeal by a

process of phagacytosis, as is usually the case with similar injuries

elsewhere. Instead, the tissues around, aided by a process of suppuration,

cast the offending portion off as a slough. It is the wound remaining after

the slough which we may really regard as a quittor. In this connection may

be considered as causes blows from falling shafts, self-inflicted treads,

or treads from other horses, overreach, etc. On the other hand, simple or

cutaneous quittor may occur without ascertainable cause. In this case we

can only explain its appearance, as we did that of simple coronitis (see p.

231), by attributing it to septic infection through a wound or a blow that

is able to inoculate the skin, yet which is insufficient to cause pain, or

in any other way attract the attendant's notice. Meanwhile, the spot of

infection thus started spreads, and the end result is an abscess in the

coronary region, again accompanied with necrosis and sloughing of more or

less skin and other tissue, which terminates by discharging its contents

and leaving behind a wound which again constitutes a cutaneous quittor.

Thus, as with simple coronitis, anything lowering the vitality of the

parts, and so favouring infection of the skin, may bring about a quittor.

Walking through much water in the winter months, through the dirt and mud

of our streets, through melting ice and snow, or through anything in the

nature of a chemical irritant, may be looked upon as a cause.

_Symptoms_.--Whether commencing from an ascertainable injury, or beginning

at first unnoticed, cutaneous quittor is characterized sooner or later by

the appearance of an inflammatory swelling, usually confined to the seat of

injury. Heat and tenderness are present, and the animal is lame.

Later the inflammatory swelling becomes more profuse, the animal is

fevered, and the symptoms of lameness increased. Poulticing is at this

stage perhaps resorted to. By its means the process of suppuration is

aided, and the swelling (at first tense and hard) either becomes gradually

softened, its contents discharged, and a simple abscess cavity left behind,

or the suppuration runs immediately round the necrosed structures, and

casts them off bodily as a slough. This latter condition is always

manifested, where the hair does not hide it, by the colour of the skin. At

first this is only red in colour--the angry red of an inflamed spot. As its

intention to slough away becomes evident, the red gradually gives way to a

gray, or even blue-black appearance, while from around it oozes a slight

discharge of pus, yellow in colour and non-offensive, or blood-stained and

dark in appearance, and foetid to the smell.

Almost invariably these symptoms are added to by a more or less diffuse and

oedematous swelling of the lower portion of the limb, extending in some

cases to as high as the fetlock or the upper third of the cannon.

With the casting off of the slough the phenomena of inflammation to a great

extent subside, the pain ceases, and the case under ordinary conditions

commences to mend.

_Pathological Anatomy_.--In its early stages the condition of simple or

cutaneous quittor is really a condition of acute coronitis (see p. 229),

and consists in an inflammation of the subcutaneous tissue, and the more

superficial portions of the coronary cushion. The tissues implicated are

destroyed outright, become infiltrated with the inflammatory exudate and

escaped blood, and act as a source of irritation to the still living

tissues around. Under the irritation the latter, as we have said before,

cast the necrosed portion away by a process of sloughing.

Always, however, it is found that the portion to be sloughed off, while

easily separated from the tissues adjacent to its sides, is closely

connected on its lowermost or deeper face with the structures below, and

cannot be torn away without hæmorrhage and the causing of acute pain.

_Prognosis_.--With wounds about the feet our forecast should always be

guarded. Even with this, the most simple form of quittor, no decided

opinion should be given until the progress of the case warrants one in

reasonably assuming that complications are absent. Once this point is

decided, a favourable prognosis may be given.

_Complications_.--With cutaneous quittor various complications may arise,

according to the extent of the invasion of the septic matter. Necrosis of

tendon, of ligament, or of cartilage, caries of the bone, or a condition of

synovitis and arthritis may be met with. As these complications are equally

common to sub-horny quittor, we shall reserve their description until

dealing with that condition. _Treatment (Preventive)_.--Immediately after

the infliction of an injury in this position, more especially if it is such

as to lead one to judge that necrosis will follow to any large extent, the

patient should be rested. Ill effects may then be probably warded off by

having the foot immersed in a cold antiseptic solution, and afterwards

bound with an antiseptic pad and bandage.

_Curative_.--When the condition has gone undiscovered until commencing

necrosis and suppuration are plainly discernible, then the wisest course we

can follow is to do all we can to hasten removal of the necrosed portion.

This is best done by promoting the suppurative process by means of warmth

or stimulant applications.

To this end hot poultices, or, better still, hot baths, should be resorted

to. Under their influence a greater supply of blood is directed to the

still healthy tissues enabling them to actively continue the inflammatory

processes necessary to the detaching of the portion necrosed, while, at

the same time, the pus organisms, stimulated by the heat, are stirred into

greater activity, and the readier accomplish their purpose of destroying

the adhesion still existing between the necrotic portion and the

surrounding living tissues.

When prolonged poulticing or bathing cannot be practised, then the swelling

should be stimulated with a sharp cantharides blister, repeated, if the

case demands it, at intervals of a few days.

Should the swelling show distinct signs of pointing, and an abscess is

plainly the condition to be dealt with, its contents should be liberated by

a free use of the knife. In this connection it is important to insist on

the fact that the opening should be made large enough. One bold incision

from the uppermost limit of the swelling down to the coronary margin of the

wall is usually sufficient.

Even when pointing is not very evident, and suppuration is plainly more or

less diffuse, benefit may still be derived from the use of the knife. In

this case a deep scarification of the part is indicated. Three, four, or

more vertical incisions are made in the swelling, and from them obtained a

flow of blood mingled with a small quantity of pus from several different

centres. By this means sloughing of the diseased portion is quickly

obtained, and nothing but an ordinary open wound left for treatment. It

should be mentioned, however, that when sloughing can be in any way induced

to take place naturally it is better to allow this to take place. Even when

the necrosed portion is freely movable, and only adherent by its base, it

should not be forcibly removed, but left to the slower but more effectual

action of the tissue reactions. If torn forcibly away, we in all

probability leave in the bottom of the wound remnants of the dead tissue,

which, being small and consequently less productive of inflammatory

phenomena, are not so readily sloughed as the larger portion. These remain

as centres of infection, and prolong the case.

Once a suitable slough has occurred, the after-treatment is simple. It

consists in dressing the wound with reliable antiseptics, and maintaining

the parts in a healthy condition until Nature completes the cure by

repairing the breach. Solutions of carbolic acid, of perchloride of

mercury, of zinc chloride, or of moderately strong solutions of copper

sulphate, are all of them useful (see also treatment of coronitis on p.

236).

It is sometimes found that even with careful attention the wound left

by the removal of the slough shows a marked disinclination to heal. The

greater portion of the cavity becomes filled with granulation tissue, and

the epidermis gradually closes round until all is covered except a spot of

perhaps the size of half a crown or a crown piece. Here the regenerative

process stops, and the wound obstinately refuses to effectually close.

In such cases we have derived excellent results with the actual cautery.

The animal is cast, the foot firmly secured by fastening it upon the cannon

of another limb, and the animal chloroformed. A practical point to be

remembered in this connection is that all necessary fixing of the limb is

easier performed if the chloroform is administered first. With the patient

thus secured we first of all ascertain by means of the probe whether or no

the non-healing of the wound is due to the presence of a fistula. Decided

in the negative, we take an ordinary flat firing-iron, and with it cut away

a portion of the skin immediately around the still open wound, carrying

our incisions deep enough to 'scoop' out a large portion of the new

inflammatory tissue beneath. With the loss of pressure from beneath,

occasioned by the removal of so much of the cicatricial tissue, the

epidermis the more readily closes over the wound. To a large extent also

this new growth of epidermis is helped by the renewal of the inflammatory

phenomena brought into being with the cauterization.

2. SUB-HORNY QUITTOR.

_Definition_.--A fistulous wound of the foot in which the lower and blind

end of the fistula is situated below the level of the coronary margin of

the wall.

_Causes_.--These, again, will be practically the same as those mentioned

in the cause of cutaneous quittor--namely, bruises, punctures, wounds--in

fact, any injury upon the coronet severe enough to cause death of tissue

and a suppurating wound. We may thus expect sub-horny quittor to follow

upon treads, overreach, accidental injuries with the stable-fork, and kicks

from other animals.

Sub-horny quittor may also arise without original injury at all to the

coronet. Either from a violent blow upon the hoof, or from the animal

himself kicking violently against a wall, death of a portion of the

sensitive structures takes place within the hoof, suppuration ensues, and

the formation of quittor commences. With the escape of the pus at the

coronet the quittor is fully formed.

Any other diseased condition of the foot in which suppuration is present

may in like manner terminate in quittor. In complicated sand-crack,

suppurating corn, or in ordinary pricked foot quittor may be a sequel. In

these conditions the pus formation either goes unnoticed or is neglected,

and after seriously invading the sensitive structures within the hoof,

breaks out at the coronet. Again, too, as with the simpler form of quittor,

and as with coronitis, we may always regard as a predisposing cause the

action of excessive cold in promoting septic infection of the wound when

occurring at the coronet.

_Symptoms and Diagnosis_.--Where the fistulous wound has had its

starting-point in an injury to the coronet diagnosis is, of course, easy.

The history of the case explains it. Nothing in this instance remains but

to probe the opening, and ascertain its direction, depth, and extent.

An animal with the wound thus open at the coronet, and freely discharging

its contents, may, if no serious complications exist, walk tolerably sound.

It is only when put to the trot that symptoms of lameness are apparent.

It may so happen, however, that we first see the case when the symptoms are

wholly those arising from a painful suppuration within the horny box.

This occurs when the original injury has taken place at a more dependent

position than the coronet. Either from violent blows upon the hoof,

puncture from below, from corn or from sand-crack, or any other causes we

have enumerated, suppuration is occurring deeply within the hoof, with as

yet no opening upon the coronet.

Even when an opening has already occurred on the coronet, the same

condition of sub-horny suppuration may be met with in cases when the

opening of the fistula has by some means or other become occluded.

Granulation tissue, for instance, may have temporarily closed the mouth of

the fistula. The pus, instead of continuing its discharge thereat, is made

to burrow in other directions.

In either of these cases pain is excessive, the animal walks on three legs,

the foot is painful to percussion, and grave constitutional disturbance

is noticeable. The presence of pus is immediately suspected, and, in the

absence of any indication of an opening having existed at the coronet,

searched for at the sole. It may or may not be found. If found it is given

exit, and the case ends as one of ordinary pricked foot, of suppurating

corn, or some other condition equally simple when compared with quittor.

In those cases where the pus is not discovered at the sole, one adopts the

expectant treatment of poulticing. This, if pus is present, is followed

by a painful swelling of the coronet. At one point there forms a hot and

tender enlargement, with the hairs on it standing straight up from the

skin, which latter is seen below red and inflamed in appearance.

Later, the abscess--for abscess it is--discharges its contents, the opening

is explored, and we find that in extent it is not confined to the coronary

region, but that it is deep enough to constitute a true sub-horny quittor.

This discharge of the abscess contents may take place at a well-defined

spot on the coronet, or it may ooze out at the junction of the wall

with the skin. In appearance the discharged pus varies. When the softer

structures only are attacked it is thick, and yellow or white in colour;

when bone is involved it is ichorous; and when attacking the horn itself

black or gray. It may or may not be extremely foetid, and often it is

mingled with blood.

When evidence of a previous opening upon the coronet is plain, then it is

not considered wise to attempt a paring of the sole. Instead, poulticing

is at once resorted to, to induce the discharge of the pus through its

original channel. Once this has occurred a fistulous wound remains, which

is open for treatment upon one or other of the lines we shall afterwards

indicate.

COMPLICATIONS--_(a) Necrosis of the Lateral Cartilage_.--This is the

so-called 'cartilaginous quittor' of other writers. In all probability it

is the condition generally understood when the word 'quittor' is used by

one practitioner to the other. Its tendency to keep the disease existing in

a chronic form renders it of grave importance, and for that reason we give

it first mention among the complications.

It may occur as a sequel either of cutaneous or of sub-horny quittor, and

may result either from actual wounding and infection of the cartilage, or

from an attack on it of septic matter originating elsewhere.

Unless there has been discovered a fistula, which on probing is seen to

lead direct to the position in which we know the cartilage to be, we

know of no precise means by which the existence of this condition may be

diagnosed. When free from other complications, the horse with his foot in

this state may travel fairly sound. This is so when the necrosis is situate

in the posterior half of the cartilage, in which case the irritation set up

by the disease is confined to the comparatively non-sensitive tissues of

the cartilage itself and the fibrous mass of the plantar cushion. When

attacking the anterior half of the cartilage, the close contiguity of the

joint renders the disease of a more serious nature. It is then that we have

acute pain, and with it extreme lameness, for in this position it is more

than likely that we have involved either the synovial membrane of the

articulation or the tops of the sensitive laminæ. It will be remembered

that here the synovial membrane protrudes as a small sac between the

antero- and postero-lateral ligaments of the joint. More or less easily

then it is bound to come into intimate contact with the septic matter

attending the necrosis of the cartilage, and so share in the inflammatory

processes, afterwards communicating them to the interior of the

articulation.

With necrosis of the lateral cartilage is always swelling and thickening of

the skin and subcutaneous structures of the coronet. This is the greater

the longer the disease has been in existence. Upon the swelling is seen the

mouth of the fistula, or it may be the mouths of several, and from them all

a discharge of pus.

The mouth of each fistula is generally filled with a mulberry-like

granulation tissue, standing above the level of the skin, and bleeding

easily if touched. The exuding pus is thin and pale gray in appearance,

gritty to the touch, and generally free from pronounced smell. At other

times its colour is reddened with contained blood, and floating in it are

tiny particles of a pale-green substance, which when picked up and rubbed

between the fingers are seen to be small fragments of the diseased

cartilage.

Should the mouth of a fistula become occluded with the granulations filling

it, and the discharge prevented from escaping, it soon happens that we have

close to the fistula that has closed a tender fluctuating swelling. This

points and breaks, and pus is again discharged from another opening. In

this manner is accounted for the multiplicity of scars and fistulas seen on

the swelling of an old-standing quittor.

The continued, inflammation thus kept in existence has the effect of

rendering the skin and subcutaneous tissues in the neighbourhood greatly

thickened and indurated. This in time leads to a tumour-like enlargement,

and causes the structures of the coronet to greatly overhang the hoof. At

the same time the constant inflammation has made its stimulant effects

noted in a great increase in the growth of the horn of the wall.

Although more abundant, however, the quality of the horn is deteriorated.

The perioplic ring has become obliterated, and the varnish-like appearance

of the healthy wall destroyed. Cracks and fissures in its surface are

numerous, and sometimes deep enough to lead to exposure of the sensitive

structures beneath, complicating the quittor with a sand-crack of a

peculiarly objectionable type.

_Pathological Anatomy of the Diseased Cartilage_.--The bulk of observers

appear to agree in the statement that in quittor the necrotic cartilage is

pea-green in colour, and recognise it by that characteristic. In size the

necrotic portion thus recognisable varies from the tiniest speck to a

portion the size of a horse-bean. Commonly, however, it is about as large

only as a pea. It is seen to be more or less detached from the rest of

the cartilage, to which it is adherent by one of its extremities only. In

general appearance we can best liken it to the split half of a green pea,

whilst others have compared it with the green sprouting of a seed. The

portions of cartilage nearest the necrotic piece are also slightly green in

colour, thus indicating that here also the diseased process has commenced.

This peculiar change of colour in the affected cartilage is of great

importance to the surgeon. It enables him when operating to distinguish

with some degree of certainty those portions of the cartilage which are

healthy and those which are not.

_(b) Necrosis of Tendon and of Ligament_.--This complication of quittor

is, as we have said before, treated by other writers as a distinct form of

the disease, and described by them under the heading of Tendinous Quittor.

This simply means, of course, that the diseased process has extended to

either of the flexor tendons, to the tendon of the extensor pedis, or,

perhaps, to the ligaments of the pedal articulation.

Of the flexor tendons, the perforans is the one commonly attacked, by

reason, of course, of its more superficial position. At times, however,

especially when its aponeurotic expansion is diseased, the necrosis of the

perforans spreads until the aponeurosis is eaten through and the phalangeal

sheath penetrated. Septic materials gain entrance thereto, and commence to

multiply. In this way the flexor perforatus is invaded, and comes to share

in the diseased process.

The extensor pedis is usually attacked by extension of the disease from a

necrotic cartilage, or results from the infliction of a severe tread in a

hind-foot. In this case the diseased structure has nothing between it and

the articulation, the synovial membrane in one position actually lining its

inner face. The result is that a condition of synovitis is easily set up,

and the case aggravated by that and by arthritis.

With the flexor tendons attacked pain is always very great, and lameness is

excessive. This, however, is not sufficiently characteristic to enable us

to determine the precise seat of the necrotic changes. Later, however, a

tender but hard enlargement made its appearance in the hollow of the heel,

which enlargement, later still, became soft and fluctuating. At this stage

there is also considerable swelling along the whole course of the tendons,

as high up as the knee or the hock. The foot is carried forward with all

the phalangeal articulations flexed, and in many cases the limb is unable

to take weight at all. Manipulated after the manner of examining the

tendons for sprain, this swelling is found to be extremely painful. The

animal flinches from the hand, and shows every sign of acute suffering.

This condition may, in fact, be mistaken for sprain, and is only to be

distinguished from it by carefully noting the history of the case--first,

the appearance of the swelling in the hollow of the heel, and, secondly,

the _after_-swelling of the upper portions of the tendons.

The formation of the abscess, the after-discharge of its contents, and the

final establishing of a fistula, are processes greatly prolonged in this

form of quittor. It will readily be understood why this should be so when

one remembers the depth at which the suppurative process is going on, the

thickness of the metacarpo-phalangeal sheath, and the resistant nature of

the material of which this latter is made, and which must be penetrated

before the condition becomes observable.

After the opening of the abscess, which usually takes place in the hollow

of the heel, there is left the fistulous wound which obstinately refuses to

heal. Or it may be, again, that there are several of these fistulas, each

opening in the heel, and the mouth of each marked by a small, ulcer-like

projection. The discharge continually oozing from these keeps the heel

constantly wet with a thick purulent discharge, which is nearly always

blood-stained, and very often foetid.

This constitutes what is known as tendinous quittor in its worst form,

for more often than not there is associated with it inflammation of

the navicular bursa, caries of the bones, or arthritis of the pedal

articulation.

With the extensor pedis attacked matters are not quite so grave, in spite

of the fact that the articulation is closely situated thereto, for in this

case the more superficial position of the diseased structure allows both

of readier exit of the discharges and of easier removal of the necrosed

portion and after-treatment of the wound.

_(c) Caries of the Bones_.--Portions of the os pedis, more especially of

its wings, and therefore usually occurring in conjunction with necrosed

cartilage, become carious in quittor. In many cases it is impossible to say

with certainty when this has occurred. In a few instances, however, the

exuding discharge gives evidence of what has happened. It is thin, but

extremely offensive, with the characteristic odour of decayed bone or

tooth, and with a feel that is gritty with contained particles of broken-up

bone. If, with a discharge of this nature present, the probe also conveys

to the fingers the sensation that bone is reached, then diagnosis may be

sure.

_(d) Ossification of the Cartilage_.--This may take place in part or in

whole. It, of course, constitutes Side-bone, a fuller description of which

will be found in a later portion of this chapter.

_(e) Penetration of the Articulation_.--This may occur either as a result

of the suppurative changes or as an accident in excision of the diseased

cartilage. Unless it is followed by a severe purulent arthritis, it is not

so grave a complication as at first sight it would appear.

_(f) Synovitis and Arthritis (Purulent)_.--Should this complication arise,

the case is a most serious one. Beyond here mentioning the fact that it may

occur, we shall not dwell on it. Fuller consideration is given to it in

Chapter XII.

_Treatment_.--The various treatments adopted for the cure of sub-horny

quittor offer the veterinary surgeon a large number to select from. We

will describe them in the order in which they are, perhaps, most commonly

practised.