hazelnut to a hickory nut, transient, with little disposition to the
formation of either blister or pustule, and usually connected with
shedding of the coat, sudden changes of weather, and unwholesomeness or
sudden change in the feed. It is most frequent in the spring and in
young and vigorous animals (good feeders). The swelling embraces the
entire thickness of the skin and terminates by an abrupt margin in place
of shading off into surrounding parts. When the individual swellings run
together there are formed extensive patches of thickened integument.
These may appear on any part of the body, and may be general; the
eyelids may be closed, the lips rendered immovable, or the nostrils so
thickened that breathing becomes difficult and snuffling. It may be
attended with constipation or diarrhea or by colicky pains. The eruption
is sudden, the whole skin being sometimes covered in a few hours, and it
may disappear with equal rapidity or persist for six or eight days.
_Treatment._--This consists in clearing out the bowels by 5 drams
Barbados aloes, or 1 pound Glauber's salt, and follow the operation of
these by daily doses of one-half ounce powdered gentian and 1 ounce
Glauber's salt. A weak solution of alum may be applied to the swellings.
PITYRIASIS, OR SCALY SKIN DISEASE.
This affection is characterized by an excessive production and
detachment of dry scales from the surface of the skin (dandruff). It is
usually dependent on some fault in digestion and an imperfect secretion
from the sebaceous glands and is most common in old horses with spare
habit of body. Williams attributes it to feed rich in saccharine matter
(carrots, turnips) and to the excretion of oxalic acid by the skin. He
has found it in horses irregularly worked and well fed and advises the
administration of pitch for a length of time and the avoidance of
saccharine feed. Otherwise the horse may take a laxative followed by
dram doses of carbonate of potash, and the affected parts may be bathed
with soft, tepid water and smeared with an ointment made with vaseline
and sulphur. In obstinate cases sulphur may be given daily in the feed.
PRURITUS, OR NERVOUS IRRITATION OF THE SKIN.
This is seen in horses fed to excess on grain and hay, kept in close
stables, and worked irregularly. Though most common in summer, it is
often severe in hot, close stables in winter. Pimples, vesicles, and
abrasions may result, but as the itching is quite as severe on other
parts of the skin, these may be the result of scratching merely. It is
especially common and inveterate about the roots of the mane and tail.
_Treatment_ consists in a purgative (Glauber's salt, 1 pound),
restricted, laxative diet, and a wash of water slightly soured with oil
of vitriol and rendered sweet by carbolic acid. If obstinate, give daily
1 ounce of sulphur and 20 grains nux vomica. If the acid lotion fails, 2
drams carbonate of potash and 2 grains of cyanid of potassium in a quart
of water will sometimes benefit. If from pinworms in the rectum, the
itching of the tail may be remedied by an occasional injection of a
quart of water in which chips of quassia wood have been steeped for 12
hours.
HERPES.
This name has been applied to a disease in which there is an eruption of
minute vesicles in circular groups or clusters, with little tendency to
burst, but rather to dry up into fine scabs. If the vesicles break, they
exude a slight, gummy discharge which concretes into a small, hard scab.
It is apparently noncontagious and not appreciably connected with any
disorder of internal organs. It sometimes accompanies or follows
specific fevers, and is, on the whole, most frequent at the seasons of
changing the coat--spring and autumn. It is seen on the lips and
pastern, but may appear on any part of the body. The duration of the
eruption is two weeks or even more, the tendency being to spontaneous
recovery. The affected part is very irritable, causing a sensitiveness
and a disposition to rub out of proportion to the extent of the
eruption.
_Treatment._--It may be treated by oxid of zinc ointment, and to relieve
the irritation a solution of opium or belladonna in water, or of sugar
of lead or oil of peppermint. A course of bitters (one-half an ounce of
Peruvian bark daily for a week) may be serviceable in bracing the system
and producing an indisposition to the eruption.
BLEEDING SKIN ERUPTIONS, OR DERMATORRHAGIA PARASITICA.
In China, Hungary, Spain, and other countries horses frequently suffer
from the presence of a threadworm (_Filaria haemorrhagica_ Railliet, _F.
multipapillosa_ Condamine and Drouilly) in the subcutaneous connective
tissue, causing effusions of blood under the scurf skin and
incrustations of dried blood on the surface. The eruptions, which appear
mainly on the sides of the trunk, but may cover any part of the body,
are rounded elevations about the size of a small pea, containing blood
which bursts through the scurf skin and concretes like a reddish scab
around the erect, rigid hairs. These swellings appear in groups, which
remain out for several days, gradually diminishing in size; new groups
appear after an interval of three or four weeks, the manifestation being
confined to three or four months of spring and disappearing in winter. A
horse will suffer for several years in succession and then permanently
recover. A fatal issue is not unknown. To find the worm the hair is
shaved from the part where the elevations are felt, and as soon as a
bleeding point is shown the superficial layer is laid open with the
knife, when the parasite will be seen drawing itself back into the parts
beneath. The worm is about 2 inches long and like a stout thread,
thicker toward the head than toward the tail, and with numerous little
conical elevations (papillae) around the head. The young worms are
numerous in the body of the adult female worm. The worm has become
common in given localities, and probably enters the system with feed or
water.
_Treatment_ is not satisfactory, but the affected surface should be kept
clean by sponging, and the pressure of harness on any affected part must
be avoided. Thus rest may become essential. The part may be frequently
washed with a strong solution of potassium sulphid.
SUMMER SORES FROM FILARIA IRRITANS.
The summer sores of horses (dermatitis granulosa, boils) have been
traced to the presence in the skin of another parasite, 3 millimeters in
length and extremely attenuated (_Filaria irritans_ Railliet). The sores
may be seen as small as a millet seed, but more frequently the size of a
pea, and may become an inch in diameter. They may appear on any point,
but are especially obnoxious where the harness presses or on the lower
parts of the limbs. They cause intense and insupportable itching, and
the victim rubs and bites the part until extensive raw surfaces are
produced. Aside from such friction the sore is covered by a
brownish-red, soft, pulpy material with cracks or furrows filled with
serous pus. In the midst of the softened mass are small, firm, rounded
granulations, fibrinous, and even caseated, and when the soft,
pultaceous material has been scraped off, the surface bears a
resemblance to the fine, yellow points of miliary tuberculosis in the
lung. The worm or its debris is found in the center of such masses.
These sores are very obstinate, resisting treatment for months in
summer, and even after apparent recovery during the cold season they may
appear anew the following summer. In bad cases the rubbing and biting
may cause exposure of synovial sacs and tendons, and cause irremediable
injury. Even in winter, however, when the diseased process seems
arrested, there remain the hard, firm, resistant patches of the skin
with points in which the diseased product has become softened like
cheese.
The apparent subsidence of the disease in winter is attributed to the
coldness and comparative bloodlessness of the skin, whereas in summer,
with high temperature, active circulation, and rapid cell growth,
inflammation is increased, itching follows, and from the animal rubbing
the part the irritation is persistently increased. The hotter the
climate the more troublesome the disease.[4]
_Treatment_ consists, first, in placing the animal in a cool place and
showering the surface with cold water. The parasite may be destroyed by
rubbing the surface of the wound with iodoform and covering it with a
layer of collodion, and repeating the applications very 24 hours for 15
days, or until the sores heal up. Ether or chloroform, poured on cotton
wool and applied to the sore for two minutes before painting it with
collodion, may be used in place of iodoform.[5]
CRACKED HEELS (SCRATCHES, OR CHAPS ON KNEE AND HOCK).
This usually sets in with swelling, heat, and tenderness of the hollow
of the heel, with erections of the hairs and redness (in white skins),
with stiffness and lameness, which may be extreme in irritable horses.
Soon slight cracks appear transversely, and may gain in depth and width,
and may even suppurate. More frequently they become covered at the
edges or throughout by firm incrustations resulting from the drying of
the liquids thrown out, and the skin becomes increasingly thick and
rigid. A similar condition occurs behind the knee and in front of the
hock (malanders and salanders), and may extend from these points to the
hoof, virtually incasing that side of the limb in a permanent incrusting
sheath.
_Causes._--Besides a heavy lymphatic constitution, which predisposes to
this affection, the causes are overfeeding on grain, unwholesome fodder,
close, hot, dirty stables, constant contact with dung and urine and
their emanations, working in deep, irritant mud; above all, in limestone
districts, irritation by dry limestones or sandy dust in dry weather on
dirt roads; also cold drafts, snow, and freezing mud, washing the legs
with caustic soap, wrapping the wet legs in thick woolen bandages which
soak the skin and render it sensitive when exposed next day, clipping
the heels, weak heart and circulation, natural or supervening on
overwork, imperfect nourishment, impure air, lack of sunshine, chronic
exhausting, or debilitating diseases, or functional or structural
diseases of the heart, liver, or kidneys. These last induce dropsical
swelling of the limbs (stocking), weaken the parts, and induce cracking.
Finally the cicatrix of a preexisting crack, weak, rigid, and
unyielding, is liable to reopen under any severe exertion; hence rapid
paces and heavy draft are active causes.
_Treatment._--In treatment the first step is to ascertain and remove the
cause whenever possible. If there is much local heat and inflammation, a
laxative (5 drams aloes or 1 pound Glauber's salt) may be given, and for
the pampered animal the grain should be reduced or replaced altogether
by bran mashes, flaxseed, and other laxative, nonstimulating feed. In
the debilitated, on the other hand, nutritious food and bitter tonics
may be given, and even a course of arsenic (5 grains arsenic with 1 dram
bicarbonate of soda daily). When the legs swell, exercise on dry roads,
hand rubbing, and evenly applied bandages are good, and mild
astringents, like extract of witch-hazel, may be applied and the part
subsequently rubbed dry and bandaged. If there is much heat but unbroken
skin, a lotion of 2 drams sugar of lead to 1 quart of water may be
applied on a thin bandage, covered in cold weather with a dry one. The
same may be used after the cracks appear, or a solution of sulphurous
acid 1 part, glycerin 1 part, and water 1 part, applied on cotton and
well covered by a bandage. In case these should prove unsuitable to the
particular case, the part may be smeared with vaseline 1 ounce, sugar of
lead 1 dram, and carbolic acid 10 drops.
INFLAMMATION OF THE HEELS WITH SEBACEOUS SECRETION (GREASE, OR CANKER).
This is a specific affection of the heels of horses usually associated
with the growth of a parasitic fungus, an offensive discharge from the
numerous sebaceous glands, and, in bad cases, the formation of red, raw
excrescences (grapes) from the surface. It is to be distinguished (1)
from simple inflammation in which the special fetid discharge and the
tendency to the formation of "grapes" are absent; (2) from horsepox, in
which the abundant exudate forms a firm, yellow incrustation around the
roots of the hair, and is embedded at intervals in the pits formed by
the individual pocks, and in which there is no vascular excrescence; (3)
from foot scabies (mange), in which the presence of an acarus is
distinctive; (4) from lymphangitis, in which the swelling appears
suddenly, extending around the entire limb as high as the hock, and on
the inner side of the thigh along the line of the vein to the groin, and
in which there is active fever, and (5) from erysipelas, in which there
is active fever (wanting in grease), the implication of the deeper
layers of the skin and of the parts beneath giving a boggy feeling to
the parts, the absence of the fetid, greasy discharge, and finally a
tendency to form pus loosely in the tissues without any limiting
membrane, as in abscess. Another distinctive feature of grease is its
tendency to implicate the skin which secretes the bulbs or heels of the
horny frog and in the cleft of the frog, constituting the disease known
as canker.
_Causes._--The predisposing causes of grease are essentially the same as
those of simple inflammation of the heel, so that the reader may consult
the preceding section. Though a specific fungus and bacteria of
different kinds are present, they tend mainly to aggravation of the
disease, and are not proved to be essential factors in causation.
_Symptoms._--The symptoms vary according to whether the disease comes on
suddenly or more tardily. In the first case there is a sudden swelling
of the skin in the heel, with heat, tenderness, itching, and stiffness,
which is lessened during exercise. In the slower forms there is seen
only a slight swelling after rest, and with little heat or inflammation
for a week or more. Even at this early stage, a slight, serous oozing
may be detected. As the swelling increases, extending up toward the hock
or knees, the hairs stand erect, and are bedewed by moisture no longer
clear and odorless, but grayish, milky, and fetid. The fetor of the
discharge draws attention to the part whenever one enters the stable,
and the swollen pastern and wet, matted hairs on the heel draw attention
to the seat of the malady. If actively treated, the disease may not
advance further, but if neglected the tense, tender skin cracks open,
leaving open sores from which vascular bleeding growths grow up,
constituting the "grapes." The hair is shed, and the heel may appear
but as one mass of rounded, red, angry excrescences which bleed on
handling and are covered with the now repulsively fetid, decomposing
discharge. During this time there is little or no fever, the animal
feeds well, and but for its local trouble it might continue at work.
When the malady extends to the frog, there is a fetid discharge from its
cleft or from the depressions at its sides, and this gradually extends
to its whole surface and upon the adjacent parts of the sole. The horn
meanwhile becomes soft, whitish, and fleshy in aspect, its constituent
tubes being greatly enlarged and losing their natural cohesion; it grows
rapidly above the level of the surrounding horn, and when pared is found
to be penetrated to an unusual depth by the secreting papillae, and that
at intervals these have bulged out into a vascular fungous mass
comparable to the "grapes."
_Treatment._--In treatment hygienic measures occupy a front rank, but
are in themselves insufficient to establish a cure. All local and
general conditions which favor the production and persistence of the
disease must be guarded against. Above all, cleanliness and purity of
the stable and air must be obtained; also nourishing diet, regular
exercise, and the avoidance of local irritants--septic, muddy, chilling,
etc. At the outset benzoated oxid of zinc ointment may be used with
advantage. A still better dressing is made with 1 ounce vaseline, 2
drams oxid of zinc, and 20 drops iodized phenol. If the surface is much
swollen and tender, a flaxseed poultice may be applied, over the surface
of which has been poured some of the following lotion: Sugar of lead,
one-half ounce; carbolic acid, 1 dram; water, 1 quart. All the
astringents of the pharmacopoeia have been employed with more or less
advantage, and some particular one seems to suit particular cases or
patients. To destroy the grapes, they may be rubbed daily with strong
caustics (copperas, bluestone, lunar caustic), or each may be tied round
its neck with a stout, waxed thread, or, finally and more speedily, they
may be cut off by a black-smith's shovel heated to redness and applied
with its sharp edge toward the neck of the excrescence, over a cold
shovel held between it and the skin to protect the skin from the heat.
The cold shovel must be kept cool by frequent dipping in water. After
the removal of the grapes the astringent dressing must be persistently
applied to the surface. When the frog is affected, it must be pared to
the quick and dressed with dry caustic powders (quicklime, copperas,
bluestone) or carbolic acid and subjected to pressure, the dressing
being renewed every day at least.
ERYSIPELAS.
This is a specific contagious disease, characterized by spreading,
dropsical inflammation of the skin and subcutaneous tissues, attended
with general fever. It differs from most specific diseases in the
absence of a definite period of incubation, a regular course and
duration, and a conferring of immunity on the subject after recovery. On
the contrary, one attack of erysipelas predisposes to another, partly,
doubtless, by the loss of tone and vitality in the affected tissues, but
also, perhaps, because of the survival of the infecting germ.
_Cause._--It is no longer to be doubted that the microbes found in the
inflammatory product are the true cause of erysipelas, as by their means
the disease can be successfully transferred from man to animals and from
one animal to another. This transition may be direct or through the
medium of infected buildings or other articles. Yet from the varying
severity of erysipelas in different outbreaks and localities it has been
surmised that various different microbes are operative in this disease,
and a perfect knowledge of them might perhaps enable us to divide
erysipelas into two or more distinct affections. At present we must
recognize it as a specific inflammation due to a bacterial poison and
closely allied to septicemia. Erysipelas was formerly known as surgical
when it spread from a wound (through which the germ had gained access)
and medical, or idiopathic, when it started independently of any
recognizable lesion. Depending as it does, however, upon a germ distinct
from the body, the disease must be looked upon as such, no matter by
what channel the germ found an entrance. Erysipelas which follows a
wound is usually much more violent than the other form, the difference
being doubtless partly due to the lowered vitality of the wounded
tissues and to the oxidation and septic changes which are invited on the
raw, exposed surface. As apparently idiopathic cases may be due to
infection through bites of insects, the small amount of poison inserted
may serve to moderate the violence.
This affection may attack a wound on any part of the horse's body,
while, apart from wounds, it is most frequent about the head and the
hind limbs. It is to be distinguished from ordinary inflammations by its
gradual extension from the point first attacked, by the abundant liquid
exudation into the affected part, by the tension of the skin over the
affected part, by its soft, boggy feeling, allowing it to be deeply
indented by the finger, by the abrupt line of limitation between the
diseased and the healthy skin, the former descending suddenly to the
healthy level instead of shading off slowly toward it, by the tendency
of the inflammation to extend deeply into the subjacent tissues and into
the muscles and other structures, by the great tendency to death and
sloughing of portions of skin and of the structures beneath, by the
formation of pus at various different points throughout the diseased
parts without any surrounding sac to protect the surrounding structures
from its destructive action, and without the usual disposition of pus to
advance harmlessly toward the surface and escape; and, finally, by a
low, prostrating type of fever, with elevated temperature of the body,
coated tongue, excited breathing, and loss of appetite. The pus when
escaping through a lancet wound is grayish, brownish, or reddish, with a
heavy or fetid odor, and inter-mixed with shreds of broken-down tissues.
The most destructive form, however, is that in which pus is deficient
and gangrene and sloughing more speedy and extensive.
_Treatment_ resolves itself mainly into the elimination from the system
of the poisonous products of the bacteria by laxatives and diuretics,
the sustaining of the failing vitality by tonics and stimulants, above
all those of the nature of antiferments, and the local application of
astringent and antiseptic agents. Internal treatment may consist in 4
drams tincture of muriate of iron and one-half dram muriate of ammonia
or chlorate of potash, given in a pint of water every two hours. To this
may be added, liberally, whisky or brandy when the prostration is very
marked. Locally a strong solution of iron, alum, or of sulphate of iron
and laudanum may be used; or the affected part may be painted with
tincture of muriate of iron or with iodized phenol. In mild cases a
lotion of 4 drams sugar of lead and 2 ounces laudanum in a quart of
water may be applied. It is desirable to avoid the formation of wounds
and the consequent septic action, yet when pus has formed and is felt by
fluctuation under the finger to be approaching the surface it should be
freely opened with a clean, sharp lancet, and the wound thereafter
disinfected daily with carbolic acid 1 part to water 10 parts, with a
saturated solution of hyposulphite of soda, or with powders of iodoform
or salol.
HORSEPOX, ANTHRAX, AND CUTANEOUS GLANDERS (FARCY).
These subjects are discussed under the head of contagious diseases.
CALLOSITIES.
These are simple thickening and induration of the cuticle by reason of
continued pressure, notably in lying down on a hard surface. Being
devoid of hair, they cause blemishes; hence, smooth floors and good
bedding should be provided as preventives.
HORNY SLOUGHS (SITFASTS), OR SLOUGHING CALLOSITIES.
These are circumscribed sloughs of limited portions of the skin, the
result of pressure by badly fitting harness or by irritating masses of
dirt, sweat, and hairs under the harness. They are most common under the
saddle, but may be found under collar or breeching as well. The sitfast
is a piece of dead tissue which would be thrown off but that it has
formed firm connections with the fibrous skin beneath, or even deeper
with the fibrous layers (fascia) of the muscles, or with the bones, and
is thus bound in its place as a persistent source of irritation. The
hornlike slough may thus involve the superficial part of the skin only,
or the whole thickness of the skin, and even of some of the structures
beneath. The first object is to remove the dead irritant by dissecting
it off with a sharp knife, after which the sore may be treated with
simple wet cloths or a weak carbolic-acid lotion, like a common wound.
If the outline of the dead mass is too indefinite, a linseed-meal
poultice will make its outline more evident to the operator. If the
fascia or bone has become gangrenous, the dead portion must be removed
with the hornlike skin. During and after treatment the horse must be
kept at rest or the harness must be so adjusted that no pressure can
come near the affected parts. (See also page 496.)
WARTS.