head" are but rarely effectual with this variety; or, if successful, too
much time has been occupied in the cure. We must look for other and more
rapid methods of treatment. These consist, first of all, in carefully
exploring the tumor for the presence of pus. The incisions must be made
over the softest part and carried deep into the tumor--to its very
bottom, if necessary--and the matter allowed to escape. After this, and
whether we have found matter or not, we must induce an active
inflammation of the tumor, in order to promote solution of the thick
walls of the abscess. This may be done by inserting well into the
incision a piece of oakum or cotton saturated with turpentine, carbolic
acid, tincture of iodin, etc., or we may pack the incision with powdered
sulphate of zinc and keep the orifice plugged for 24 hours. These agents
set up a destructive inflammation of the walls. Suppuration follows, and
this should now be encouraged by hot fomentations and poultices. The
orifice must be kept open, and should it be disposed to heal we must
again introduce some of the agents above described. A favored treatment
with many, and it is probably the best, is to plunge a red-hot iron to
the bottom of the incision and thoroughly sear all parts of the walls of
the abscess. This is to be repeated after the first slough has taken
place if the walls remain thickened and indurated.
It is useless to waste time with fomentations, poultices, or blisters in
the treatment of cold abscesses, since though apparently removed by such
methods, they almost invariably return when the horse is put to work.
Extirpation by the knife is not practicable, as the walls of the tumor
are not sufficiently defined. If treated as above directed, and properly
fitted with a good collar after healing, there will not remain any track
or trace of the large, unsightly mass.
FISTULAS.
_Definition._--The word fistula is applied to any ulcerous lesion upon
the external surface of the body which is connected by ducts, or
passages, with some internal cavity. Because of this particular
formation the term fistulous tract is often used synonymously with the
word fistula. Fistulas may exist in any part of the body, but the name
has come to be commonly accepted as applicable only to such lesions when
found upon the withers. Poll evil is a fistula upon the poll, and in no
sense differs from fistulous withers except in location. The description
of fistula will apply, then, in the main, to poll evil equally well.
Quittor presents the characteristic tubular passages of a fistula and
may, therefore, be considered and treated as fistula of the foot.
Fistulous passages may also be developed upon the sides of the face,
through which saliva is discharged instead of flowing into the mouth,
and are called salivary fistulas. A dental fistula may arise from the
necrosis of the root of a tooth. Again, a fistula is sometimes noted at
the umbilicus associated with hernia, and recto-vaginal fistulas have
been developed in mares, following difficult parturition. Fistulas may
arise from wounds of glandular organs or their ducts, and thus we have
the so-called mammary or lacrimal fistulas.
Fistulous tracts are lined with a false, or adventitious, membrane and
show no disposition to heal. They constantly afford means of exit to the
pus or ichorous material discharged by the unhealthy parts below. They
are particularly liable to develop at the withers or poll because of the
exposed positions which these parts occupy, and, having once become
located there, they usually assert a tendency to further extension,
because the vertical and laminated formation of the muscles and tendons
of these parts allows the forces of gravitation to assist the pus in
gaining the deeper-lying structures and also favors its retention among
them.
_Causes._--Fistulas follow as a result of abscesses, bruises, wounds, or
long-continued irritation by the harness. Among the more common causes
of fistula of the poll (poll evil) are chafing by the halter or heavy
bridle; blows from the butt end of the whip; the horse striking his head
against the hayrack, beams of the ceiling, low doors, etc. Fistulous
withers are seen mostly in those horses that have thick necks as well as
those that are very high in the withers; or, among saddle horses, those
that are very low in the withers, the saddle here riding forward and
bruising the parts. In either of these locations ulcers of the skin, or
simple abscesses, if not properly and punctually treated, may become
fistulas. They are often caused by bad-fitting collars or saddles, by
direct injuries from blows, and from the horse rolling upon rough or
sharp stones. The pus burrows and finds lodgment deep down between the
muscles, and escapes only when the sinus becomes surcharged or when,
during motion of the parts, the matter is forced to the surface.
_Symptoms._--These, of course, will vary according to the progress made
by the fistula. Following an injury we may often notice soreness or
stiffness of the front legs, and upon careful examination of the withers
we see small tortuous lines running from the point of irritation
downward and backward over the region of the shoulder. These are
superficial lymphatics, and are swollen and painful to the touch. In a
day or two a swelling is noticed on one or both sides of the dorsal
vertebrae, which is hot, painful, and rapidly enlarging. The stiffness of
the limbs may disappear at this time, and the heat and soreness of the
parts may become less noticeable, but the swelling remains and continues
to enlarge.
A fistulous ulcer of the poll may be first indicated by the opposition
which the animal offers to the application of stable brush or bridle. At
this time the parts are so sore and sensitive that there is some danger
that unless handled with the greatest care the patient will acquire
disagreeable stable habits. The disease in its early stages may be
recognized as a soft, fluctuating tumor surrounded by inflammatory
swelling, with the presence of enlarged lymphatic vessels and stiffness
of the neck. Later the inflammation of the surrounding tissues may
disappear, leaving a prominent tumor. The swelling, whether situated
upon the head or the withers, may open and form a running ulcer, or its
contents may dry up and leave a tumor which gradually develops the
common characteristics of a fibrous tumor. When the enlargement has
opened we should carefully examine its cavity, as upon its condition
will wholly depend our treatment.
_Treatment._--In the earliest stage, when there is soreness, enlarged
lymphatics, but no well-marked swelling, the trouble may frequently be
aborted. To do this requires both general and local treatment. A physic
should be given, and the horse receive 1 ounce of powdered saltpeter
three times a day in his water or feed. If the fever runs high, 20-drop
doses of tincture of aconite root every two hours may be administered.
The local application of cold water to the inflamed spot for an hour at
a time three or four times a day has often proved very beneficial, and
has afforded great relief.
Cooling lotions, muriate of ammonia, or saltpeter and water; sedative
washes, such as tincture of opium and aconite, chloroform liniment, or
camphorated oil, are also to be frequently applied. Should this
treatment fail to check the progress of the trouble, the formation of
pus should be hastened as rapidly as possible. Hot fomentations and
poultices are to be constantly used, and as soon as the presence of pus
can be detected, the abscess wall is to be opened at its lowest point.
In this procedure lies our hope of a speedy cure. As with any simple
abscess, if drainage can be so provided that the pus will run off as
fast as formed without remaining within the interstices of the tissues,
the healing will be rapid and satisfactory.
Attention is again called to the directions given above as to the
necessity of probing the cavity when opened. If upon a careful
examination with the probe we find that there are no pockets, no
sinuses, but a simple, regular abscess wall, the indication for
treatment is to make an opening from below so that all the matter must
escape. Rarely is anything more needed than to keep the orifice open and
to bathe or inject the parts with some simple antiseptic wash that is
not irritant or caustic. A low opening and cleanliness constitute the
essential and rational treatment.
If the abscess has already opened, giving vent to a quantity of purulent
matter, and the pipes and tubes leading from the opening are found to be
extensive and surrounded with thick fungoid membranes, there is
considerable danger that the internal ligaments or even some of the
bones have become affected, in which case the condition has assumed a
serious aspect. Or, on the other hand, if the abscess has existed for
some time without a rupture, its contents will frequently be found to
consist of dried purulent matter, firm and dense, and the walls
surrounding the mass will be found greatly thickened. In such a case we
must generally have recourse to the application of caustics which will
cause a sloughing of all of the unhealthy tissue, and will also
stimulate a rapid increase of healthy organized material to replace that
destroyed in the course of the development and treatment of the disease.
Threads or cords soaked in gum-arabic solution and rolled in powdered
corrosive sublimate may be introduced into the canal and allowed to
remain. The skin on all parts of the shoulder and leg beneath the
fistula should be carefully greased with lard or oil, as this will
prevent the discharge that comes from the opening after the caustic is
introduced from irritating or blistering the skin over which it flows.
In obstinate cases a piece of caustic potash (fused) 1 to 2 inches in
length may be introduced into the opening and should be covered with
oakum or cotton. The horse should then be secured so that he can not
reach the part with his teeth. After the caustic plug has been in place
for 24 hours, it may be removed and hot fomentations applied. As soon as
the discharge has become again established the abscess should be opened
from its lowest extremity, and the passage thus formed may be kept open
by the introduction of a seton. If the pipes become established in the
deep tissues beneath the shoulder blade or among the spines of the
vertebral column, it will often be found impossible to provide proper
drainage for the abscess from below, and treatment must consist of
caustic solutions carefully injected into all parts of the suppurating
sinuses. A very effective remedy for this purpose consists of 1 ounce of
chlorid of zinc in half a pint of water, injected three times during a
week, after which a weak solution of the same may be occasionally
injected. Injections of Villate's solution or alcoholic solution of
corrosive sublimate, strong carbolic acid, or possibly oil of turpentine
will also prove beneficial. Pressure should be applied from below, and
endeavors made to heal the various pipes from the bottom.
Should the swelling become general, without forming a well-defined
tumor, the placing of 20 to 30 grains of arsenious acid, wrapped in a
single layer of tissue paper, in a shallow incision beneath the skin,
will often produce a sloughing of the affected parts in a week or 10
days, after which the formation of healthy tissue follows. The
surrounding parts of the skin should be protected from any damage from
escaping caustics by the application of lard or oil, as previously
suggested.
Although the successful treatment of fistulas requires time and
patience, the majority of cases are curable. The sinuses must be opened
at their lowest extremity and kept open. Caustic applications must be
thoroughly used once or twice, after which mild astringent antiseptic
washes should be persistently used until a cure is reached.
It sometimes happens that the erosions have burrowed so deeply or in
such a direction that the opening of a drainage passage becomes
impracticable. In other cases the bones may be attacked in some
inaccessible location, or the joints may be affected, and in these cases
it is often best to destroy the horse at once.
The reappearance of the fistula after it has apparently healed is not
uncommon. The secondary attack in these cases is seldom serious. The
lesion should be carefully cleaned and afterwards injected with a
solution of zinc sulphate, 20 grains to the ounce of water, every second
or third day until a cure is effected.
In fistula of the foot we see the same tendency toward the burrowing of
pus downward to lower structures, or in some cases upward toward the
coronet. Prior to the development of a quittor there is always swelling
at the coronet, accompanied with heat and pain. Every effort should now
be made to prevent the formation of an abscess at the point of injury.
Wounds caused by nails, gravel, or any other foreign body which may have
lodged in the sole of the foot should be opened at once from below, so
as to allow free exit to all purulent discharges. Should the injury have
occurred directly to the coronet the application of cold fomentations
may prove efficient in preventing the formation of an abscess.
When a quittor becomes fully established it should be treated precisely
as a fistula situated in any other part of the body; that is, the
sinuses should all be opened from their lowest extremities, so as to
afford constant drainage. All fragments of diseased tissue should be
trimmed away, antiseptic solutions injected, and, after covering the
wound with a pad of oakum saturated with some good antiseptic wash, the
whole foot may be carefully covered with clean bandages, which will
afford valuable assistance to the healing process by excluding all dirt
from the affected part.
Another form of treatment for this class of infections consists in the
use of bacterial vaccines. Such treatment appears to be well adapted for
the purpose, and according to current veterinary literature has met with
success. These vaccines are composed of several strains of the organisms
usually found in these pustular infections of the horse. Two kinds of
vaccines are used: First, autogenic vaccines, which consist of heated
(killed) cultures of the organism or organisms which are causing the
trouble and which have been isolated from the lesions; second, stock
vaccines, consisting of dead organisms of certain species generally
found in these lesions and which are used in diseased conditions caused
by one or the other of these germs. The vaccine is administered
subcutaneously by means of a syringe, but the quantity of the vaccine to
be injected and the number of doses to be used should be left to the
judgment of a competent veterinarian.
INFECTIOUS DISEASES.
By RUSH SHIPPEN HUIDEKOPER, M. D., Vet.
[Revised by A. Eichhorn, D. V. S.]
GENERAL DISCUSSION.
An infectious disease may be defined as any malady caused by the
introduction into the body of minute organisms of the vegetable or
animal kingdom which have the power to multiply indefinitely and set
free certain peculiar poisons which are chiefly responsible for morbid
changes. Nearly all diseases of animals for which a definite cause may
be attributed are caused by bacteria; such are tuberculosis, anthrax,
blackleg, lockjaw, and others. There are some diseases, as, for
instance, Texas fever and rabies, which are caused by a minute animal
parasite known as protozoa, while others again, like lumpy jaw and
aspergillosis, are caused by fungi. Besides there are infectious
diseases in which the causative agents have never been successfully
isolated, as they are so small that they can not be detected by the aid
of the most powerful microscope, and accordingly they are termed as
ultravisible viruses. Hog cholera, foot-and-mouth disease, smallpox, and
others belong to this group.
Bacteria may be defined as very minute unicellular organisms of
plantlike character. They multiply either by simple division or by spore
formation, the latter usually taking place when the conditions
pertaining to the growth of the bacteria become unfavorable. The spores
are much more resistant to destruction than the bacteria which produce
them.
Another group of parasites producing disease is known as protozoa. These
are more complex than bacteria, and their artificial cultivation is also
much more difficult than is the case with the bacterial parasites. Of
the representatives of this group, causing disease in animals, are the
trypanosomes, which are the causative factors of dourine and surra, and
the piroplasma, which induce Texas fever in cattle and malaria or
biliary fever of horses. There are also disease-producing fungi which
are responsible for certain affections in horses; among these the most
important are mycotic lymphangitis, or sporotrichosis, and
streptotrichosis.
The introduction of the infection may take place in various ways. The
most frequent method is by ingestion. Further, the entrance of the
germs may occur by inhalation, skin abrasions, wounds of any kind,
through the genital organs, and at times also through the milk ducts of
the teats. As a general rule infectious diseases have a period of
incubation which comprises the time elapsing between the exposure to the
infection and the actual appearance of the disease. This period varies
in the different diseases.
The treatment of infectious diseases is, as a rule, unsatisfactory. When
the symptoms have once appeared a disease is liable to run its course in
spite of treatment, and if it is one from which animals usually recover,
all that can be done is to put them into the most favorable
surroundings. Many infectious diseases lead sooner or later to death;
treatment is useless so far as the sick animals are concerned, and it
may be worse than useless for those not yet affected. All animals
suffering with infectious diseases are more or less directly a menace to
all others. They represent for the time being manufactories of disease
germs, and they are giving them off more or less abundantly during the
period of disease. They may infect others directly or they may scatter
the virus about and the surroundings may become the future source of
infection.
Therefore, in the control of infectious diseases prevention is the most
important procedure. The isolation or segregation of healthy animals
from infected ones should be primarily considered, and if at any time an
animal manifests the symptoms of an infectious disease it is essential
to protect the others from such a source of danger. In some of the
infectious diseases it may become advisable to kill the infected animals
in order to avoid the spread of the disease. This is especially
important in diseases which are slow in their course, such as
tuberculosis. At times when diseases appear in a country where they have
not been prevalent it becomes advisable and necessary to protect the
healthy herds by the slaughter of all the infected animals. Pursuance of
this policy has resulted in control of the foot-and-mouth disease, and
has proved to be a very satisfactory method of eradication.
DISINFECTION.
Disinfection is a very important phase in the control of infectious
disease. This consists in the use of certain substances which possess
the power to destroy bacteria or their spores, or both. The cheapest and
most available for animal diseases are ordinary freshly slaked lime, or
unslaked lime in powder form, chlorid of lime, crude carbolic acid,
corrosive sublimate, formalin, formaldehyde, gas, cresol, etc.
In the disinfection of stables and premises it is essential to execute
the work in a most thorough manner. This may be satisfactorily
accomplished by carrying out the following directions:
1. Sweep ceilings, side walls, stall partitions, floors, and other
surfaces until free from cobwebs and dust.
2. Scrape away all accumulation of filth, and if woodwork has become
decayed, porous, or absorbent, it should be removed, burned, and
replaced with new material.
3. If floor is of earth, remove 4 inches from the surface, and in places
stained with urine a sufficient depth should be replaced to expose fresh
earth. All earth removed should be replaced with earth from an
uncontaminated source; it would be better still to lay a new floor of
concrete, which is very durable and easily cleaned.
4. All refuse and material from stable and barnyard should be removed to
a place not accessible to cattle or hogs. The manure should be spread on
fields and turned under, while the wood should be burned.
5. The entire interior of the stable, especially the feeding troughs and
drains, should be saturated with a disinfectant, as liquor cresolis
compositus (U. S. P.), or carbolic acid, 6 ounces to every gallon of
water, to which 4 ounces of chlorid of lime should be added. The best
method of applying the disinfectant and the lime wash is by means of a
strong spray pump, such as those used by orchardists. This method is
efficient in disinfection against most of the contagious and infectious
diseases of animals, and should be applied immediately following any
outbreak, and, as a matter of precaution, it may be used once or twice
yearly.
6. It is important that arrangements be made to admit a plentiful supply
of sunlight and fresh air by providing an ample number of windows,
thereby eliminating dampness, bad odor, and other insanitary conditions.
Good drainage is also very necessary.
If the use of liquor cresolis compositus, carbolic acid, or other
coal-tar products is inadmissible because of the readiness with which
their odor is imparted to milk and other dairy products, bichlorid of
mercury may be used in proportion of 1 to 800, or 1 pound of bichlorid
to 100 gallons of water. All portions of the stable soiled with manure,
however, should first be thoroughly scraped and cleaned, as the albumin
contained in manure would otherwise greatly diminish the disinfecting
power of the bichlorid. Disinfection with this material should be
supervised by a veterinarian or other person trained in the handling of
poisonous drugs and chemicals, as the bichlorid is a powerful, corrosive
poison. The mangers and the feed boxes, after drying, following spraying
with this material, should be washed out with hot water, as cattle are
especially susceptible to mercurial poisoning. The bichlorid solution
should be applied by means of a spray pump, as recommended for the
liquor cresolis compositus.
VACCINATION.
In recent years vaccination for the prevention of certain infectious
diseases has been successfully developed, and without a doubt the future
has a great deal in store for this phase of prevention. At the present
time vaccination has been found effective against blackleg, hog cholera,
anthrax, lockjaw, strangles, rabies, hemorrhagic septicemia, white
scours, etc. It is always essential, of course, that the products used
for the vaccination be pure and potent; also they should be employed
only with the advice of competent authorities and with proper care. The
biological products prepared for the cure and prevention of infections
are prepared by manufacturers who, in order to conduct an interstate
business, are required to obtain a license from the United States
Department of Agriculture for the manufacture of such preparations.
Since July 1, 1913, the Department of Agriculture, by an act of Congress
of March 4, 1913, has had control of the manufacture of biological
products for the treatment of domestic animals. The numerous complaints
which were received from time to time relative to the impotency of some
of the preparations, and also the fact that in some instances the use of
the products were directly responsible in causing outbreaks of disease,
made the necessity for such control obvious. This supervision is no
doubt of far-reaching importance, as it assures the users that the
preparations are reliable.
INFLUENZA.
_Synonyms._--Pinkeye, typhoid fever, epizooty, epihippic fever,
hepatic fever, bilious fever, etc.; flevre typhoide, grippe
(French); Pferdestaupe (German); gastro-enteritis of Vatel and
d'Arboval; febris erysipelatodes, Zundel; typhus of Delafond.
_Definition._--The term influenza is applied to a febrile, contagious,
infectious disease of horses, which is characterized by a blood
infection, with inflammation of the mucous membranes, which frequently
involves the lungs. Inflammatory complications also occur in the form of
swellings of the subcutis, tendons, and tendinous sheaths and laminae of
the feet. The causative agent has not been satisfactorily established.
One attack usually protects the animal from future ones of the same
disease, but not always. An apparently complete recovery is sometimes
followed by serious sequelae of the nervous and blood-vessel systems.
Under certain conditions of the atmosphere or from unknown causes, the
disease is very liable to assume an epizootic form, with tendency to
complications of especial organs, as, at one period, the lungs, at
another the intestines, etc.