DISEASES OF THE FORE-LIMB
SPRAINS AND INJURIES IN THE REGION OF THE SHOULDER.--Sprains and injuries
of the structures in the shoulder region are more common in horses that are
called on to do heavy work than among driving horses.
The following _causes_ may be mentioned: Ill-fitting collars, pulling heavy
loads over uneven streets or soft ground, where the footing is not secure,
and slipping are common causes. Young horses that do not know how to pull,
or horses that are tired out by hard work, are predisposed to muscular
strain, and are apt to suffer injury if forced to do heavy work. Sore
shoulders, or an ignorant driver, may cause the animal to pull awkwardly
and throw more strain on certain groups of muscles than they can stand.
Rheumatism frequently causes shoulder lameness. The muscle usually affected
by rheumatism is the large muscle extending from the region of the point of
the shoulder to the summit of the head.
[Illustration: FIG. 31.--Shoulder lameness.]
_The symptoms_ of shoulder lameness vary in the different cases. The horse
may walk without going lame, but when made to trot lameness is quite
noticeable. The animal may point with the foot of the diseased limb,
holding it forward, but squarely on the floor. In severe strain, little
weight is thrown on the limb and the lameness is marked (Fig. 31). In
"shoulder slip" the head of the arm bone pushes outward every time the
animal throws weight on the limb. This luxation can be noticed best when
standing in front of the animal. Marked atrophy of the external shoulder
muscles may occur. Such atrophy may appear and disappear quickly, and may
result from an injury to the nerve supply of the muscle as well as from
favoring the part. Atrophy of the shoulder may occur if the animal is lame
in other regions of the limb, especially the feet. The outcome of shoulder
lameness is favorable if the disease causing it is given prompt treatment.
_Rest_ is a very important part of the _treatment_. It may be advisable to
restrict the horse's movements by placing it in a single stall, and tying
the animal so that it can not lie down. This should be continued for at
least one week. If the horse is restless, it should be given a box-stall or
turned out in a small lot alone. It should be watered and fed in the
quarters where confined. The _local treatment_ consists in applying mild
liniments or blisters to the shoulder. It is not advisable, however, to
apply a blister if the muscles feel hot and tender.
CAPPED ELBOW, "SHOE-BOIL."--Capped elbow is an inflammation of the bursa at
the posterior surface of the elbow (Fig. 32). The swelling that results is
usually sharply defined. It may feel abnormally warm and doughy, and it may
be painful. Later, the enlargement may be well defined and hard. Sometimes
the skin is indurated and lies in folds, or the shoe-boil shows abrasions
on its surface and fistulous openings leading from abscess centres. The
cystic or soft tumor is a common form. Such an enlargement fluctuates on
pressure, and when opened, a blood-stained fluid escapes. All forms of
capped elbow tend to become chronic.
_The treatment_ is both preventive and local. As capped elbow is caused by
bruising the part with the hoof or heel of the shoe, the preventive
treatment consists in hindering the animal from taking a position that may
favor injury to the part. Confining the animal in a small stall and tying
it with too short a halter strap favors a sternal position when lying down.
A roomy stall that permits the animal to stretch or change position is an
important preventive measure. Shoes that project beyond the quarters should
be avoided. The elbow may be protected by placing a thick pad over the
heels when the animal is in the stable.
[Illustration: FIG. 32.--Shoe-boil.]
_Local treatment_ varies according to the character of the enlargement.
Soft, doughy swellings may be treated by application of cold, iodine and
blisters. The cystic form of tumor must be opened, the fluid removed and
the lining membrane destroyed by the injection of tincture of iodine. Hard,
indurated shoe-boils may be treated by completely removing the diseased
tissue. The surgical treatment of capped elbow requires the service of an
experienced veterinarian. His efforts may prove a complete failure, unless
the irritation to the part by the shoe or hoof is prevented.
INJURIES TO THE KNEE (BROKEN KNEE).--Horses frequently fall and bruise or
lacerate the knee when moving at trot or canter. The injury varies
according to the force of the fall, and the character of the road that the
animal is travelling over. Some individuals are more liable to suffer from
this class of injuries than others. Horses that are weak-kneed because of
poor conformation, or knee-sprung, are inclined to stumble. Careless
driving, especially if the animal is tired, predisposes it to this class of
injury. Because of the predisposition toward stumbling on the part of some
horses, scars on the front of the knee are termed broken knee, and the
animal is considered unsound.
_The symptoms_ vary with the extent of the injury. Slight bruises or
abrasions result in local swelling and soreness that disappear within a few
days. Laceration of skin interferes with the movement of the knee and the
animal may be quite lame. The part becomes swollen and painful. In injuries
involving the sheaths of the tendons and the synovial membrane, the pain is
severe and the accompanying inflammation may take on a serious form.
_The preventive treatment_ should not be overlooked. Horses should be
trained to carry the head at a proper height when moving. The driver should
handle the reins properly and keep his attention on the horse or horses
that he is driving. Superficial bruises require no special treatment other
than rest. Laceration of the skin and underlying tissue requires complete
rest and careful removal of any particles, of dirt and gravel that may be
present in the wound. Shreds of tissue that may take no part in the healing
should be cut away. The hair in the region of the wound should be trimmed
short. Careful and repeated dressings with antiseptics are necessary until
the inflammation has largely disappeared and healing is rapidly taking
place. It may be advisable to tie the horse in the stall so that it can not
lie down.
DISTENDED SYNOVIAL SACS, JOINT SHEATHS AND BURSAE, "GALLS."--Soft
enlargements may occur in the region of the knee and fetlock. They are
commonly termed "galls," "wind-galls," or "road-puffs." They are usually
due to the sheaths surrounding the tendons becoming distended with synovia.
"Galls" are caused by strains, direct injury to the part and severe,
continuous work. Certain individuals may develop this class of blemishes
without being subject to any unusual conditions. This condition is seldom
accompanied by lameness.
_The treatment_ may vary in the different cases. If the distended sheath,
or bursal enlargement, is caused by a direct injury or strain, cold
bandages should be applied and the part given as complete rest as possible.
"Wind-galls" may be removed by a surgical operation. It is not advisable to
attempt the removal of "road-puffs." Rest, stimulating leg washes and
bandages may temporarily remove the latter.
SPRUNG KNEES (BUCK KNEES).--This condition of the knee is characterized by
the partly flexed condition of the region. It is best observed by standing
to one side of the horse (Fig. 33). Instead of the forearm and cannon
regions appearing perpendicular or in line, they are directed forward. This
condition may exist in varying degrees. Some individuals show it to a
slight degree, the condition being accompanied by a weakness or shakiness
of the knee when standing at rest. Sometimes, but one knee is involved.
_The causes_ of this unsoundness are hereditary and accidental. Weak knees
due to faulty conformation seldom escape becoming sprung in animals that
are given hard work. Severe and continuous driving is a common factor in
the production of this condition. Strains of the flexor muscles of the
region may cause it. The retraction of the flexor muscles and their tendons
and the aponeurosis of the antibrachial region occurs in this disorder and
prevents the animal from extending the knee.
The region is greatly weakened by this condition and the animal may be
unfitted for active work. For this reason the value of the animal is
greatly diminished.
_Treatment_ is unsatisfactory. The preventive treatment consists in not
breeding animals that have poorly conformed knees and using the proper
judgment in working young horses and when driving or riding horses. Certain
cases may be greatly benefited by sectioning the tendons of the external
and middle flexors of the metacarpi. To insure a successful outcome in any
case that is operated on, a long period of rest is required.
[Illustration: FIG. 33.--Sprung knees.]
[Illustration: FIG. 34.--Splints.]
SPLINTS.--A splint is a bony enlargement situated along the line of
articulation between the splint and cannon bones (Fig. 34). This blemish is
due to an inflammation of the periosteum. It is a very common blemish and
is generally located along the splint bones of the forefeet, especially the
internal ones.
_Splints are caused_ by strains and rupture of the ligament that binds the
splint bone to the cannon bone. The result is an inflammation of the
periosteum. Slipping, or an unbalanced condition of the foot, may cause
this injury by distributing the weight unequally on the splint bones.
Faulty action and bad shoeing may cause the horse to strike and bruise the
region.
_Symptoms of lameness_ are not always present. A high splint involving the
articulation between the lower row of carpal, splint and cannon bones may
be considered an unsoundness, because of the persistent character of the
lameness. The animal may show little or no lameness when walked, but if
moved at a trot, especially over a hard roadway, it may show marked
lameness. The local inflammation is characterized by a small swelling lying
along the splint bone, that feels hot and may pit on pressure. After a time
the inflammation disappears and is replaced by a hard, bony enlargement.
When this occurs the lameness disappears.
_The preventive treatment_ consists in keeping the feet of young horses in
proper balance by frequent trimming and proper shoeing. This attention is
very necessary in young colts that are running in pasture. It is very
advisable to rest the animal during the period of inflammation. Cold
bandages should be applied. As soon as the inflammation has subsided mild
counterirritants and absorbents may be used. In. case the lameness
persists, more severe counterirritation is indicated.
INFLAMMATION OF THE FLEXOR TENDONS OF THE DIGIT.--The large tendons
posterior to the foot and the suspensory ligament that separates them from
the cannon bone frequently become inflamed. Sometimes complete rupture of
one or more of these structures occurs. The lighter breeds of horses are
the most frequent sufferers. Because of the greater strain thrown on the
tendons of the forefeet, inflammation of these tendons is far more common
than it is in the hindfoot. Diseased conditions of the hind tendons are
usually due to other causes than strain.
The following _predisposing_ and _accidental causes_ should be considered:
Weak flexor tendons and heavy bodies predispose animals to inflammation of
the tendons and suspensory ligament; quality, not size, is the factor to
consider when judging the strength of a tendon; long, slender pasterns
increase the strain on these structures, and this mechanical strain is
further increased by low heels and long toes; the character of the work and
the condition of the road that the animal travels over are important
factors to consider; trotting and running horses more often suffer from
injuries to tendons and ligaments than draft horses; travelling at a high
rate of speed over an uneven road, slipping and catching the foot in a rut
or car track, are common causes; bruises and wounds may result in the
tendons becoming inflamed; inflammation of the tendinous sheaths and the
tendons as well sometimes occurs in influenza.
_Lameness_ is a prominent _symptom._ The pastern is held in a more upright
position than normal. When the animal is standing, the foot is rested on
the toe, and it may take advantage of any uneven place on which to rest the
heel. In severe strains the local symptoms are quite prominent. The tendons
may be hot and swollen. Pressure may cause the animal pain. In chronic
tendinitis the tendon may be thickened and rough or knotty. Pain is not a
prominent symptom in this class of cases. Shortening of the inflamed tendon
may occur, causing the animal to knuckle over. Rupture of one or more of
the tendons and the suspensory ligament can be recognized by the abnormal
extension of the pastern. If the ruptured tendon heals, it always results
in a thickening at the point of the rupture that gives the tendons a bowed
appearance. This is termed bowed-tendon.
The lameness resulting from an inflammation of tendons resembles that
resulting from strains and injuries to the fetlock joint, especially in the
region of the sesamoid bones.
INFLAMMATION OF THE SESAMOID BONES differs slightly from the former.
Pressure over the posterior region of the fetlock may cause the animal
pain. The lameness shows a tendency to disappear with rest and reappear
when the animal is again worked. Lameness is most prominent in some cases
when the animal is first moved out. There may be a lack of local symptoms,
such as heat and swelling. It is not uncommon for a bony enlargement to
form on the sesamoid bone after a few months or a year.
The following _treatment_ is recommended. Horses that have a poor quality
of tendon and weak fetlocks and pasterns should not be used for breeding
purposes. Careful driving would prevent a large percentage of injuries to
tendons. The most important treatment for all injuries due to strains is
rest. In all cases of severe strain to the structures in this region, it is
very advisable to apply a plaster bandage. This should be left on for at
least two weeks. When the acute inflammation has subsided, counterirritants
may be applied. Either cold or hot applications are recommended. Cold
applications are to be preferred at the beginning of the inflammation.
Covering the tendons with a cold bandage, or with a heavy layer of
antiphlogistin, is recommended. The horse should not be worked until after
the tendons have had an opportunity to completely recover from the
inflammation.
CONTRACTED TENDONS, KNUCKLING-OVER.--New-born foals are sometimes unable to
stand on their front feet because of the excessive knuckling-over. The colt
may walk on the front of the pastern and fetlock. This sometimes results in
severe injury to the skin and the underlying tissues.
Knuckling-over in the mature horse is not always due to contracted tendons.
It may occur as a symptom of inflammation of the flexor tendons, ligaments
of the fetlock joint and the articulation as well. It may be noticed in
animals that have ring-bone, or coffin-joint lameness.
The most _common cause_ for this unsoundness is inflammation of the muscles
and tendons of the flexors of the digit. As a result of long standing or
severe inflammation, shortening of these structures occurs in consequence
of the contraction of the inflammatory or cicatricial tissue.
Knuckling-over in the newborn colt is commonly caused by a weakness or lack
of innervation of the extensor muscle of the digit. Judging from the quick
recovery that usually occurs, other causes for this condition are seldom
present.
_The treatment_ recommended for the new-born colt is supporting the fetlock
with a light plaster bandage. This should be applied very soon after birth
in order to prevent bruising of the fetlock. A light cheese-cloth bandage
should be applied to the limb from the hoof to the knee. The colt is laid
on its side, the toe extended as much as possible, and the plaster bandage
applied. This should be removed in about one week and fresh bandages
applied. In about two weeks the young animal is usually able to walk on the
toe. As soon as it is able to do this a bandage is unnecessary. It is not
advisable to turn the colt outside if there is any chance for the bandages
to become wet.
Knuckling-over due to faulty conformation is difficult to correct. Light
work and careful shoeing are the most valuable preventive measures in young
horses. Sprains and injuries to the region of the fetlock should receive
the necessary treatment. The treatment for contracted tendon is largely
surgical and consists in sectioning it.
INJURIES CAUSED BY INTERFERING.--Horses that have faulty action may strike
the opposite fetlock with the moving foot, the inside of the opposite limb
in the region of the knee, and the quarters of the front foot with the shoe
of the hindfoot. It is very common for horses to "brush" the inside of the
hind fetlock with the opposite foot when trotting, especially if tired.
Interfering in the front feet is less common. Striking the inside of the
region of the knee with the opposite foot or "_speedy cutting_" occurs in
driving and speed horses. Both of the latter forms of interfering may be
considered unsoundnesses.
The most _common cause_ of interfering is faulty conformation, such as
narrowness of the chest or pelvis, faulty conformation of the limbs and
irregularity in the action of the joints. Shoeing and the condition of the
feet are also important factors. Animals that have a narrow chest or pelvis
interfere because the legs are placed too closely together. Turning in of
the knees or "knock-kneed," winging in or out of the feet, or any other
defective conformation of the limbs that tends to prevent the animal from
moving the feet in line, lead to serious interfering. A wide-spreading
hoof, an unbalanced condition of the foot and improper fitting of the shoes
are common causes for interfering in horses that would otherwise move the
feet in line. Debility from disease and overwork may cause the animal to
interfere temporarily. An unbalanced gait and shortness of the body are the
common causes for injuries to the quarters.
All degrees of injury to the part struck by the shoe or wall of the foot
may be noted. Horses that interfere lightly, wear the hair off and produce
slight abrasions of the skin on the inside of the fetlock. Sometimes the
skin is bruised, inflamed or scarred. Injuries to the inside of the knee
and quarter are the most serious. Lameness, inflammation of the periosteum
and bony enlargement may result from "speedy cutting." Deep wounds in the
region of the heel or quarter may occur when a horse strikes this part with
the shoe of the hindfoot in moving at a high rate of speed.
_The treatment_ is largely preventive. No doubt many cases of interfering
could be prevented by careful training and balancing of the foot when the
animal is growing and developing. The feet of colts should be trimmed every
three or four weeks. Interfering in the hindfeet may be stopped by noting
the character of the animal's gait and the portion of the wall that strikes
the part, and by practising intelligent methods of shoeing. Slight injuries
should be treated by the application of antiseptic powders. The treatment
for injuries to the periosteum is the same as that recommended for splints.
As a last resort boots and button rings may be used for the purpose of
preventing serious injury to that part which is struck by the foot.
RING-BONE.--Chronic inflammation of the articulation between the first and
second bones of the digit is termed ring-bone (Fig. 35). Not all ring-bones
involve the articular surfaces. The periarticular, or false ring-bone, is a
chronic inflammation of the bone near the articular surface. The bony
enlargement varies in size. It may form a ring encircling the part, or it
may be limited to the lateral surface of the joint. The bony enlargement
may be so small as to be detected only by a careful examination. Ring-bone
may occur on any of the feet, but it is said to be more common in the front
feet.
[Illustration: FIG. 35.--Bones of digit, showing side bones and ring-bones,
and normal bones of digit.]
_The predisposing cause_ of ring-bone is faulty conformation. Long, weak
pasterns that are predisposed to strains, upright pasterns, especially if
small, and exposed to concussion and jarring, and crooked feet that
distribute the weight on the part irregularly are important factors in the
production of ring-bones. The _external causes_ are sprains or any injury
to the region. _Lameness_ is nearly always present. The degree of lameness
varies, and does not depend altogether on the size of the bony enlargement.
Large ring-bones interfere with the movement of the tendon. Lameness is
most pronounced when weight is thrown on one foot, the later phase of the
step being shortened and the pastern more upright. Some cases improve with
rest, but the lameness returns when the animal is given hard work.
_The preventive treatment_ consists in giving the necessary attention to
the feet of young animals, by trimming the wall frequently and keeping the
feet in balance and the careful selection of breeding stock. Resting the
animal, keeping the foot that has the ring-bone on it in proper balance and
counterirritation by means of blisters and cautery (searing) are important
lines of treatment. Shortening the toe and raising the heel, if necessary,
greatly relieves the lameness in some cases. Sectioning the sensory nerves
that go to the part should not be practised, unless in exceptional cases.
QUESTIONS
1. Give the causes of shoulder lameness; give the treatment.
2. Describe capped elbow; give the treatment.
3. What is "broken knee"?
4. What are "wind-galls" and "road-puffs"?
5. Give the cause and treatment of sprung-knee.
6. Give the cause and treatment of splints.
7. What class of horses most commonly have strained tendons? Give the
causes and treatment of this form of lameness.
8. Give the treatment of contracted tendons in the new-born colt.
9. Give the causes for interfering.
10. What are the different forms of ring-bone? Give the causes and
treatment of ring-bone.