complication, and even when present in its most limited form is always a
serious matter; but when it becomes extensive, and especially when the
suppurative process extends to the periosteum, the results are liable to
be fatal. When suppuration occurs the exudation does not appear to be
excessive. It is rich in leucocytes and seems to have caused detachment
of the sensitive tissues from the horn prior to the formation of pus in
some instances; in others the tissues are still attached to the horn,
and the suppuration takes place in the deeper tissues.
Limited suppuration may take place in any part of the sensitive tissues
of the foot during laminitis, and may ultimately be reabsorbed instead
of being discharged upon the surface, but generally the process begins
in the neighborhood of the toe and spreads backward and upward toward
the coronet, finally separating the horn from the coronary band at the
quarters. At the same time it spreads over the sole and eventually the
entire hoof is loosened and sloughs away, leaving the tissues beneath
entirely unprotected. In other instances--and these are generally the
cases not considered unusually severe--the suppuration begins at the
coronary band. It extends but a short distance into the tissues, yet
destroys the patient by separating the hoof from the coronary band, upon
which it depends for support and growth. This form of the suppurative
process usually begins in front. It is this part of the coronary band
that is always most actively affected with inflammation, and
consequently it is here that impairments first occur.
Suppuration of the sensitive sole is more common than of the sensitive
laminae and coronary band. It is present in the majority of cases in
which there is a dropping of the coffin bone, and in other instances
when the effusion at this point is so great as to arrest the production
of horn and uncover the sensitive tissues. Except when the result of
injury it begins at the toe and spreads backward, and, if not relieved
by opening the sole, escapes at the heel. Suppuration of the sole is
much less serious than in other parts of the foot.
If the acute constitutional symptoms developed from sloughing of the
foot do not result in death, a new hoof of very imperfect horn may be
developed after a time; but unless the animal is to be kept for breeding
purposes alone the foot will ever be useless for work and death should
relieve the suffering. When only the sole sloughs, recovery takes place
with proper treatment.
_Peditis._--This is the term that Williams applies to that serious
complication of laminitis in which not only the laminae, but the
periosteum membrane covering the bone and coffin bone also are subjects
of the inflammatory process. Neither is this all; in some of these cases
of peditis acute inflammation of the coffin joint is present, and
occasionally suppuration of the joint. A mild form of periostitis, in
which the exudation is in the outer layer of the periosteum only, is a
more common condition than is recognized generally by practitioners.
Intimate contiguity of structures is the predisposing cause, for the
disease either spreads from the original seat or the complication occurs
as one of the primary results of the exciting cause. In the severer
cases in which the exudate separates the periosteum from the bone,
suppuration, gangrene, and superficial caries are common results. If
infiltration of the bone tissues is rapid the blood supply is cut off by
pressure upon the vessels and death of the coffin bone follows. Grave
constitutional symptoms mark these changes, which soon prove fatal.
In the mild cases of periostitis it is by no means easy positively to
determine its presence, for there are no special symptoms by which it
may be distinguished from pure laminitis. In a majority of acute cases,
though, which show no signs of improvement by the fifth to seventh day,
it is safe to suspect periostitis, particularly if the coronets are very
hot, the pulse full and hard, and the lameness acute. In the fortunately
rare cases in which the bone is affected with inflammation and
suppuration the agony of the patient is intense; he occupies the
recumbent position almost continually, never standing for more than a
few minutes at a time; suffers from the most careful handling of the
affected feet; maintains a rapid pulse and respiration, high
temperature, loss of appetite, and great thirst. It is in these cases
that the patient continually grows worse, and the appearance of
suppuration at the top of the hoof in about two weeks after the
inception of the disease proves the inefficiency of any treatment which
may have been used and the hopelessness of the case. These patients die
usually between the tenth and twentieth days either from exhaustion or
pyemic infection.
_Gangrene_ occurs in the periosteum as the result of excessive
detachment from the bone and compression due to excessive exudation.
Other parts of the sensitive tissues are subject occasionally to the
same fate, and at times large areas will be found dead.
_Pumiced sole_ is that condition in which the horny sole in the
neighborhood of the toe readily crumbles away and leaves the sensitive
tissues more or less exposed. It is not a complication of laminitis
only, for it is seen under other conditions. Williams has described the
horny tissue of pumiced sole as "weak, cheesy, or spongy, like macerated
horn, or even grumous (thick, clotted)." Crumbling horn, when critically
examined, shows almost an entire absence of the cohesive matter which
unites the healthy fibers, while the fibers themselves are irregular
and granular in appearance. Pumiced sole depends upon an impairment of
the horn-secreting powers of the sensitive sole or upon a separation of
the horny from the soft tissues which maintain its vitality.
Punctured wounds of the foot, accompanied with any considerable
destruction of the soft tissues, present the same peculiarities of horn
in the immediate neighborhood of the injury. Bruises of the sole are
followed by this change when the exudation has been excessive and has
separated the horn from the living tissues. True, in these cases we
rarely see the soft tissues laid bare, for the reason that new horn is
constantly secreted and replaces that undergoing disintegration.
Laminitis presents three conditions under which pumiced sole may appear:
First, when free exudation separates the horn from the other tissues, or
when the process of inflammation arrests the production of horn by
impairing or destroying the horn-secreting membrane; second, when
depression of the coffin bone causes pressure upon and arrests the
formation of horn; and, third, when the elevation of the sole compresses
the soft tissues against the pedal bone and induces the same condition.
Pumiced sole, from simple exudation and separation of tissues, is of
little importance for the reason given above in connection with bruises;
but when suppuration occurs in restricted portions of the foot in
conjunction with laminitis, it always lays bare the tissues beneath and
temporarily impairs the animal's value. Recovery takes place after a few
weeks by the tissues "horning over," as in injuries attended by the same
process. Depression of the coffin bone is not sufficient within itself
to cause pumiced sole; for, if the relative change in the bone takes
place slowly, or if the horn is thin, the sole becomes convex from
gradual pressure and the soft tissues adapt themselves to the change
without having their function materially impaired. But when the dropping
is sudden and the soft tissues are destroyed, the horn rapidly crumbles
away and the toe of the bone comes through. In many of these cases the
soft tissues remain uncovered for months. When they are eventually
covered it is with a thin, slightly adherent horn that stands but little
or no wear. The sole being now convex, the diseased tissues bear unusual
weight by coming in contact with the ground, and hence it is that these
animals are generally incurable cripples.
In most cases in which the sole is raised to meet the pedal bone and
pumiced sole occurs it is due not to pressure of the bone from within
(for the tissues are capable of adapting themselves to the gradual
change) but to impaired vitality of the sensitive tissues from the
inflammation and to the constant concussion and pressure applied from
without during progression. To this is to be added the paring away of
the horn when applying the shoe, thereby keeping the sole at this point
too thin.
_Turning up of the toe._--In many cases of laminitis which have become
chronic it is found that the toe of the foot turns up; that the heels
are longer than natural; while the hoof near the coronary band is
circled with ridges like the horn of a ram. Even in cases in which
recovery has taken place, and in other diseases than laminitis, these
ridges may be found in the wall of the foot. In such cases, however, the
ridges are equally distant from one another all around the foot, while
in turning up of the toe the ridges are wide apart at the heels and
close together in front, as seen in the figure. (Plate XXXVII, fig. 4.)
These ridges are produced by periods of interference with the growth of
horn alternating with periods during which a normal or nearly normal
growth takes place. When the toe turns up it is because the coronary
band in front produces horn very slowly, while at the heels it grows
much faster, causing marked deformity.
Animals so affected always place the abnormally long heel first upon the
ground, not alone because the heel is too long, nor as in acute or
subacute laminitis to relieve the pain, but for the reason that the toe
is too short and lifted away from its natural position. To bring the toe
to the ground the leg knuckles at the fetlock joint.
The pain and impairment of function in these cases always result in
marked atrophy of the muscles of the forearm and shoulder, and to some
extent of the pectorals, while the position of the fore legs advances
the shoulder joints so far forward as to cause a sunken appearance of
the breast, which the laity recognize as "chest founder."
The lesions of turning up of the toe are permanent, and are the most
interesting pathologically of all the complications of laminitis.
_Treatment._--The treatment of laminitis is probably more varied than of
any other disease, and yet a large number of cases recover for even the
poorest practitioner.
_Prevention._--To guard against and prevent disease, or to render an
unpreventable attack less serious than it otherwise would be, is the
highest practice of the healing art. In a disease so prone to result
from the simplest causes, especially when the soundest judgment may not
be able to determine the extent of the disease-resisting powers of the
tissues which are liable to be affected, or of what shall in every
instance constitute an overexcitement, it is not strange that horse
owners find themselves in trouble from unintentional transgression. If
the disease were dependent upon specific causes, or if the stability of
the tissues were of a fixed or more nearly determinate quality, some
measures might be instituted that would prove generally preventive; but
the predisposing causes are common conditions and often can not be
remedied. That which is gentle work in one instance may incite disease
in another. That which is feed to-day may to-morrow prove disastrous to
health. Finally, necessary medical interference, no matter how
judicious, may cause a more serious complaint than that which was being
treated. Notwithstanding these difficulties there are some general rules
to be observed that will in part serve to prevent the development of an
unusual number of cases. First of all the predisposing causes must be
removed when possible; when impossible, unusual care must be taken not
to bring an exciting cause into operation. Under no circumstances should
fat animals have hard work. If the weather is warm or the variation of
temperature great, all horses should have but slow, gentle labor until
they become inured to it, the tissues hardened, and their excitability
reduced to a minimum. Green horses should have moderate work,
particularly when taken from the farm and dirt roads to city pavements;
for under these circumstances increased concussion, changed hygienic
conditions, and artificial living readily become active causes of the
disease. Army horses just out of winter quarters, track horses with
insufficient preparation, and farmers' horses put to work in the spring
are among the most susceptible classes, and must be protected by work
that is easy and gradual. If long marches or drives are imperative, the
incumbrances must be as light as possible and the journey interspersed
with frequent rests, for this allows the laminae to regain their impaired
functional activity and to withstand much more work without danger.
Furthermore, it permits early detection of an attack, and prevents
working after the disease begins, which renders subsequent medication
more effective by cutting the process short at the stage of congestion.
All animals when resting immediately after work should be protected from
cold air or drafts. If placed in a stable that is warm and without
draft, no covering is necessary; under opposite conditions blankets
should be used until the excitement and exhaustion of labor have
entirely passed away. It is still better that all animals coming in warm
from work be "cooled out" by slow walking until the perspiration has
dried and the circulation and respiration are again normal. Animals
stopped on the road even for a few moments should always be protected
from rapid change of temperature by appropriate clothing. If it can be
avoided, horses that are working should never be driven or ridden
through water. If unavoidable, they should be cooled off before passing
through, and then kept moving until completely dried. The same care is
to be practiced with washing the legs in cold water when just in from
work, for occasionally it proves to be the cause of a most acute attack
of this disease. Unusual changes in the manner of applying the shoes
should not be hastily made. If a plane shoe has been worn, high heels or
toes must not be substituted at once; but the change, if necessary,
should gradually be made, so that the different tissues may adapt
themselves to the altered conditions. If radical changes are imperative,
as is sometimes the case, the work must be so reduced in quantity and
quality that it can not excite the disease.
Laminitis from the effects of purgatives can scarcely be guarded
against. I can not determine from the cases in which I have seen this
result that there are any conditions present that would warn us of
danger. The trouble does not seem to depend upon the size of the
purgative, the length of time before purgation begins, or the activity
and severity with which the remedy acts. Medicines known to have
unusually irritating effects on the alimentary canal should be used only
when necessity demands it, and then in moderate doses.
Experience alone will determine what animals are liable to suffer from
this disease through the use of feeds. When an attack can be ascribed to
any particular feed it should be withheld, unless in small quantities.
Horses that have never been fed upon Indian corn should receive but a
little of it at a time, mixed with bran, oats, or other feed, until it
has been determined that no danger exists. Corn is less safe in warm
than in cold weather, and for this reason it should always be fed with
caution during spring and summer months.
When an animal is excessively lame in one foot the shoe of the opposite
member should be removed, and cold water frequently applied to the well
foot. At the same time, if the subject remains standing, the slings
should be used. Horses should under no circumstances be overworked; to
guard against this, previous work, nature of roads, state of weather,
and various other influences must be carefully considered. Watering
while warm is a pernicious habit, and, unless the animal is accustomed
to it, is liable to result in some disorder, ofttimes in laminitis.
_Curative measures._--In cases of simple congestion of the laminae the
body should be warmly clothed and warm drinks administered. The feet
should be placed in a warm bath to increase the return flow of blood. In
course of an hour the feet may be changed to cold water and kept there
until recovery is completed. If the constitutional symptoms demand it,
diuretics should be given. Half-ounce doses of saltpeter three times a
day in the water answer the purpose. In cases of active congestion the
warm footbaths should be omitted and cold ones used from the
commencement. Subacute laminitis demands the same treatment, with
laxatives if there is constipation, and the addition of low-heeled
shoes. The diuretics may need to be continued for some time and their
frequency increased. Regarding acute laminitis, what has been called the
"American treatment" is simple and efficient. It consists solely in the
administration of large doses of nitrate of potash and the continued
application to the feet and ankles of cold water.
Three to four ounces of saltpeter in a pint of water, repeated every six
hours, is a proper dose. The laminitis frequently subsides within a
week. These large doses may be continued for a week without danger.
Under no circumstances have I seen the kidneys irritated to excess or
other unfavorable effects produced.
The feet should be kept in a tub of water at a temperature of 45 deg. to 50 deg.
F., unless the animal is lying down, when swabs are to be used and wet
every half hour with the cold water. The water keeps the horn soft and
moist and acts directly upon the inflamed tissues by reducing the
temperature. Cold maintains the vitality and disease-resisting qualities
of the soft tissues, tones up the coats of the blood vessels, diminishes
the supply of blood, and limits the exudation. Furthermore, it has an
anesthetic effect upon the diseased tissues and relieves the pain.
Aconite may be given in conjunction with the niter when the heart is
greatly excited and beats strongly. Ten-drop doses, repeated every 2
hours for 24 hours, are sufficient. The use of cathartics is dangerous,
for they may excite superpurgation. Usually the niter will relieve the
constipation; yet if it should prove obstinate, laxatives may be
carefully given. Bleeding, both general and local, should be guarded
against. The shoes must be early removed and the soles left unpared.
Paring of the soles presents two objections: First, while it may
temporarily relieve the pain by relieving pressure, it favors greater
exudation, which may more than counterbalance the good effects.
Secondly, it makes the feet tender and subject to bruises when the
animal again goes to work. The shoes should be replaced when
convalescence sets in and the animal is ready to take exercise. Exercise
should never be enforced until the inflammation has subsided; for
although it temporarily relieves the pain and soreness it maintains the
irritation, increases the exudation, and postpones recovery.
If at the end of the fifth or sixth day prominent symptoms of recovery
are not apparent, apply a stiff blister of cantharides around the
coronet and omit the niter for about 48 hours. When the blister is well
set, the feet may again receive wet swabs. If one blister does not
remove the soreness it may be repeated, or the actual cautery applied.
The same treatment should be adopted where sidebones form or
inflammation of the coronet bone follows. When the sole breaks through,
exposing the soft tissues, the feet must be carefully shod with thin
heels and thick toes if there is a tendency to walk on the heels, and
the sole must be well protected with appropriate dressings and pressure
over the exposed parts. When there is turning up of the toe, blistering
of the coronet, _in front only_, sometimes stimulates the growth of
horn, but as a rule judicious shoeing is the only treatment that will
enable the animal to do light, slow work.
When suppuration of the laminae is profuse, it is better to destroy your
patient at once and relieve his suffering: but if the suppuration is
limited to a small extent of tissue, especially of the sole, treatment,
as in acute cases, may induce recovery and should always be tried. If
from bed sores or other causes septicemia or pyemia is feared, the
bisulphite of soda, in half-ounce doses, may be given in conjunction
with tonics and such other treatment as is indicated in these diseases.
As to enforced recumbency I doubt the propriety of insisting on it in
the majority of cases, for I think the patient usually assumes whatever
position gives most comfort. No doubt recumbency diminishes the amount
of blood sent to the feet, and may greatly relieve the pain, so that
forcing the patient to lie down may be tried, yet should not be renewed
if he thereafter persists in standing.
When the animal persistently stands, or constant lying indicates it (to
prevent extensive sores), the patient should be placed in slings. When
all four feet are affected it may be impossible to use slings, for the
reason that the patient refuses to support any of his weight and simply
hangs in them. Lastly, convalescent cases must not be returned to work
too early, else permanent recovery may never be effected.
DISEASES OF THE SKIN.
By JAMES LAW, F. R. C. V. S.,
_Formerly Professor of Veterinary Science, etc., Cornell University._
As we find them described in systematic works, the diseases of the skin
are very numerous and complex, which may be largely accounted for by the
fact that the cutaneous covering is exposed to view at all points, so
that shades of difference in inflammatory and other diseased processes
are easily seen and distinguished from one another. In the horse the
hairy covering serves to some extent to mask the symptoms, and hence the
nonprofessional man is tempted to apply the term "mange" to all alike,
and it is only a step further to apply the same treatment to all these
widely different disorders. Yet even in the hairy quadruped the
distinction can be made in a way which can not be done in disorders of
that counterpart and prolongation of the skin--the mucous membrane,
which lines the air passages, the digestive organs, the urinary and
generative apparatus. Diseased processes, therefore, which in these
organs it might be difficult or impossible to distinguish from one
another, can usually be separated and recognized when appearing in the
skin.
Nor is this differentiation unimportant. The cutaneous covering presents
such an extensive surface for the secretion of cuticular scales, hairs,
horn, sebaceous matter, sweat, and other excretory matters, that any
extensive disorder in its functions may lead to serious internal disease
and death. Again, the intimate nervous sympathy of different points of
the skin with particular internal organs renders certain skin disorders
causative of internal disease and certain internal diseases causative of
affections of the skin. The mere painting of the skin with an
impermeable coating of glue is speedily fatal; a cold draft striking on
the chest causes inflammation of the lungs or pleura; a skin eruption
speedily follows certain disorders of the stomach, the liver, the
kidneys, or even the lungs; simple burns of the skin cause inflammations
of internal organs, and inflammation of such organs cause in their turn
eruptions on the skin. The relations--nervous, secretory, and
absorptive--between the skin and internal organs are most extensive and
varied, and therefore a visible disorder in the skin may point at once
and specifically to a particular fault in diet, to an injudicious use of
cold water when the system is heated, to a fault in drainage,
ventilation, or lighting of the stables, to indigestion, to liver
disease, to urinary disorder, etc.
[Illustration: PLATE XXXVIII.
THE SKIN AND ITS DISEASES.]
STRUCTURE OF THE SKIN.