Chapter X: Section III: Lameness in the Fore Leg (4)

Where contraction exists to the extent that the subject can not stand and where no weight is borne by the feet, it is necessary to divide the affected tendons surgically. The same technic is put into practice that is employed in the mature subject but there is much greater chance for a favorable outcome in the foal. Further, if necessary, one may divide with impunity, both tendons on each leg, at the same time. In all cases this operation is done by observing strict aseptic precautions and the legs are, of course, bandaged. If both tendons are divided, splints should be employed and kept in position for ten days or two weeks. Primary union of the small surgical wound of the skin and fascia occurs in forty-eight hours.

The reader is referred to William's "Veterinary Surgical and Obstetrical Operations," for a complete description of this operation.

In veterinary literature there is occasionally described a
condition which affects young foals wherein symptoms similar to
those of contraction of the flexors are manifested, but upon
examination it is found that rupture of the extensor of the digit
(extensor pedis) exists. This affection is briefly described by
Cadiot but no complete treatise on this condition has been
published.

In parts of Canada foals of from one to three days of age are found
affected in such manner that more or less interference with the
gait is to be seen in those moderately affected. There is, in some
subjects, only a slight impediment in locomotion which is
occasioned by inability to properly extend the digit. In other
subjects, while able to stand and walk, great difficulty is
experienced because of volar flexion of the phalanges. The more
seriously affected animals are unable to stand and, in most
instances, perish because of the effects of prolonged decubitus.

A local enlargement occurs at the anterior carpal region and the
mass is somewhat fluctuating, extravasated fluids becoming infected
in many instances, and necrosis of the skin and fascia provide
means for spontaneous discharge of the contents of the enlargement
if it is not opened. The infection when it becomes generalized
causes a fatal termination in most cases that are not treated.

Native stock owners of some parts of Canada know this condition as
"fish knees" because of the presence of the ruptured end of the
extensor tendon which is found coiled in the cavity of the
enlargements caused by the ruptured tendon.

Local practitioners have treated the condition by incising the
swollen mass and removing the part of tendon contained within such
cavities. Treatment has not proved entirely satisfactory in the
majority of instances, perhaps because of tardy interference.

In a colt's leg sent the author by Mr. Thomas Millar, M.R.C.V.S.,
of Asquith, Saskatchewan, a careful dissection of the carpal region
revealed the fact that in this case the ruptured extensor tendon
was due to injury. The colt may have been trampled upon by its dam
in such manner that the tendon was divided. No noticeable evidence
of injury to the skin was to be seen on its outer surface, but on
the fascial side a cyanotic congested area, which was situated
immediately over the site of the ruptured tendon, was very
evident.

With the execution of a good surgical technic, the ruptured tendon
might be sutured; the wound of the tendon sheath as well as that of
the skin carefully united by means of gut sutures, the leg bandaged
and immobilized with leather splints and recovery follow in a
reasonable percentage of cases so treated. These cases afford an
opportunity for the perfection of practical means of treatment by
those who frequently meet with this affection.

Rupture of the Flexor Tendons and Suspensory Ligament.

Etiology and Occurrence.--Rupture of the flexor tendons or of the suspensory ligament is of rare occurrence. Frequently, these structures are divided as the result of wounds; but rupture, due to strain, is not frequent.

In some cases in running horses, or in animals that are put to strenuous performances, such as are jumpers, rupture of tendons or of the suspensory ligament takes place. However, more frequently this follows certain debilitating diseases such as influenza or local infectious inflammation of the parts which results in degenerative changes and rupture follows.

The non-elastic suspensory ligament receives some heavy strains during certain attitudes which are taken by horses in hurdle jumping as is explained in detail by Montané and Bourdelle[26] under the description of this ligament. But in spite of the frequent and unusually heavy strains, which these structures receive, complete rupture is not frequently seen.

Symptomatology.--When the anatomy and function of the flexor tendons and suspensory ligament is thoroughly understood, recognition of rupture of either of these structures is easily recognized. When one considers that in rupture, a position directly opposite to that which is seen in contraction in either one of these structures, is assumed, a detailed description of each separate condition is needless repetition.

However, it is pertinent to suggest that rupture of the deep flexor tendon (perforans) allows a turning up of the toe. Whether it be torn loose from its point of attachment or ruptured at some point proximal thereto, the position is the same--heel flat on the ground, toe slightly raised and this raising of the toe varies in degree as the subject moves about.

When the superficial flexor (perforatus) is ruptured there is no change in the position of the foot but the fetlock joint is slightly lowered. The pathognomonic symptom is the lax tendon during weight bearing, which may be felt by palpation of the tendon along its course in the metacarpal region.

With complete rupture of the suspensory ligament there occurs a marked dropping of the fetlock joint and an abnormal amount of weight is then thrown upon the superficial flexor tendon (perforatus), causing it to be markedly tensed. This is readily recognized by palpation. By palpating the suspensory ligament from its proximal portion down to and beyond its bifurcation, while the affected member is supporting weight, it is possible to diagnose rupture of one of its branches.

Prognosis and Treatment.--In rupture of the superficial flexor tendon (perforatus) because of its comparatively less important function, prognosis is favorable and recovery takes place when proper treatment is put into practice.

With rupture of the deep flexor tendon (perforans), especially when it occurs at or near its point of insertion and sometimes following disease, prognosis is unfavorable.

Rupture of the suspensory ligament constitutes a condition which is, as a rule, hopeless, because of the impracticability of treating such cases.

The salient feature which characterizes any practical attempt at treatment of ruptured tendons or other portions of the inhibitory apparatus of the fetlock region, is to retain the phalanges in their normal position for a sufficient length of time that the approximated ends of ruptured tendons or ligaments may unite. The length of time required for this to occur, together with the difficulties encountered in confining the affected extremities in suitable braces or supportive appliances, precludes all possibility of this condition's being practically amenable to treatment when the deep flexor tendon (perforans) and suspensory ligament are simultaneously ruptured. It does not follow, even so, that recovery does not succeed treatment in some of these unfavorable cases.

Affected subjects are kept in slings as long as it seems necessary--until they learn to get up without deranging the braces worn.

Several styles of braces are in use and each has its objections; nevertheless some sort of support to the affected member is necessary and steel braces which are connected with shoes are usually employed.

The principal difficulty which attends the use of braces is pressure-necrosis of the skin which is caused by the constant and firm contact of the metal support. The practitioner's ingenuity is taxed in every case to contrive practical means of padding the exposed parts in order to prevent or minimize necrosis from pressure. This is attempted--with more or less success--by frequent changing of bandages and the local application of such agents as alcohol or witch hazel. Needless to say, the skin must be kept perfectly clean and the dressings free from all irritating substances.

The fact that tendons or ligaments which are ruptured, do not regenerate as readily as in cases where traumatic or surgical division occurs, must not be lost sight of, and prognosis is given in accordance.

Thecitis and Bursitis in the Fetlock Region.

Etiology and Occurrence.--Synovial distension of tendon sheaths and bursae in the region of the fetlock are caused by the same active agencies which produce this condition in other parts. The fetlock region is exposed to more frequent injury than is the carpus and as a consequence is more often affected. The same proportionate amount of irritation affects this part of the leg, owing to strains, as affect the carpus from a similar cause; and synovitis from this cause, is as frequent in one case as in the other. Therefore, it is a natural sequence that the tendon sheaths of the metacarpophalangeal region are frequently distended because of chronic synovitis and thecitis. These inflammations are usually non-infective in character.

The _cul-de-sac_ of the capsular ligament of the fetlock joint which extends upward between the bifurcation of the suspensory ligament is the most frequently affected structure in this region. When distended, two spheroidal masses bulge laterally and anterior to the flexor tendons in a characteristic manner. This condition is known among horsemen as "wind-gall" or "fetlock-gall."

The sheath of the flexor tendons, which begins about the middle portion of the lower third of the metacarpus, and continues downward below the pastern joint is often distended.

Excepting in cases of acute inflammation attending synovitis of these parts, no lameness marks its existence and in chronic cases of synovial distension the service of affected animals is not interfered with. These distensions constitute unsightly blemishes and they are treated chiefly for this reason.

No difficulty is encountered in recognizing these conditions even where considerable organization of tissue overlying distended thecae occurs. In such cases there may be only slight fluctuation of the enlargement, but if necessary, an aseptic exploratory puncture may be made with a suitable needle or trocar.

Treatment.--Complete rest and the local application of cold packs are in order in acute synovitis when there is distension of tendon sheaths. In the fetlock region, because of the ease with which pressure may be employed, the parts should be kept snugly wrapped with cotton, and derby bandages are used to exert the desired amount of pressure over the affected region. The pressure-bandages should be employed as soon as all acute and painful inflammation has subsided; and then they should be continued, day and night, for ten days or two weeks. The bandages should be removed morning and night. After the skin of the leg has thoroughly dried off, an infriction of alcohol or distilled extract of hamamelis is given the parts and the cotton and bandages are readjusted. A good, even and firm pressure in such cases is productive of satisfactory results.

In chronic distensions of tendon sheaths synovia may be aspirated and about five cubic centimeters of equal parts of tincture of iodin and alcohol is injected into the cavity. This is not done, however, without usual aseptic precautions. If no marked swelling results within forty-eight hours the entire fetlock region is thoroughly vesicated and, as soon as the skin has recovered from the effects of the vesicant, pressure bandages may be employed. In these cases, subjects may be put into service after all swelling which the injection or the vesicant has produced has subsided. The pressure bandages are used at night or during the time that the horse is in its stall and they are not worn by the subject while at work.

Where no marked swelling occurs within ten days, as the result of the injection of iodin, the injection may be repeated and, if thought necessary, the quantity may be materially increased. If swelling does not occur it is indicative that no particular irritation has been caused.

Some swelling is desirable and much swelling sometimes results and persists for weeks. This is not in any way likely to cause permanent trouble; and if the technic of injection is skilfully executed no infection will follow.

By persistent and careful use of suitable elastic bandages, the support thus given the parts, together with the absorption of products of inflammation which constant pressure occasions, some chronic cases of synovial distension of tendon sheaths recover in two or three months and this without other treatment. Such good results are not to be expected in aged subjects, nor in horses having at the same time, chronic lymphangitis.

Where bandages of pure rubber are employed great care is necessary, if one is not experienced in their use, lest necrosis result. Where bandages are uncomfortably tight the subject will manifest discomfort, and an attendant should observe the animal at intervals for a few hours (where there may be some doubt as to the degree of pressure which is exerted by elastic bandages) and readjustment made before any harm is done.

Arthritis of the Fetlock Joint.

Anatomy.--The anatomy of the metacarpophalangeal articulation is briefly reviewed on page 58 under the heading of "Anatomo-Physiological Review of Parts of the Foreleg."

Etiology and Occurrence.--The chief causes of non-infective arthritis of the fetlock joint are irritations from concussion and contusions due to interfering. The condition occurs in young animals that are over-driven in livery service or other similar exhausting work, where they become so weary that serious injury is done these parts by striking the pasterns with the feet--interfering. In these "leg-weary" animals, that are always kept shod with fairly heavy shoes, much direct injury is done at times by concussion due to self-inflicted blows. In older animals, where there exists similar conditions, with respect to their being worn from fatigue and, in addition, periarticular inflammatory organizations, arthritis is not of uncommon occurrence.

Symptomatology.--In true arthritis there exists a very painful affection which is characterized by manifestations of distress. The subject may keep the extremity moving about--where pain is great--suspended and swinging. There is swelling which is more or less hot to the touch and compression of the parts with the fingers increases pain. Lameness is always pronounced and no weight is supported with the affected member in very acute and generalized arthritic inflammations. There occurs the usual facial manifestations of pain--the tense condition of the facial muscles and the fixed eye and nostril are in evidence.

In cases where there exists a synovitis or where a very limited portion of the articulation is involved, a somewhat different clinical picture is presented. Then, the disturbance causes less distress; local swelling and evidence of supersensitiveness are not so pronounced and lameness is not intense, though weight-bearing is painful.

Prognosis.--There is a constant difference in the degree of pain manifested, as well as the other symptoms of inflammation, between true arthritis, which involves much of the joint, and synovitis; or synovitis plus a small circumscribed area of joint involvement. This difference is present in all joint affections of the extremities and, in passing, it is well to say that infection usually increases every manifestation of pain. Infection occasions more pronounced local symptoms of inflammation and, because of the rapid progress of necrotic destruction of cartilage, the course of the affection is usually rapid; ankylosis is a frequent result and loss of the subject is often inevitable. However, in non-infective arthritis of the fetlock joint, prognosis is favorable.

Treatment.--The same general principles which are employed in arthritis of other joints are used here. Rest and comfort for the patient is sought in every available manner. If the subject remains standing too long, the sling should be used and a well-bedded box-stall will contribute much to the comfort of the patient.

Pain and acute inflammation is diminished or controlled, if possible, by using ice-cold packs. In nervous, well-bred animals analgesic agents may be employed; or small doses of morphin sulphate--one to two grains--given at intervals of three hours during the first stages of the affection is very beneficial. This is especially indicated in infectious arthritis.

As inflammation subsides, hot applications are used and finally counter irritants are employed. Their selection is a matter of choice with the practitioner. The object sought is the same with every practitioner and while methods employed vary, results are not markedly different except in so far as the degree of counter irritation which is produced varies in given cases. Where a great degree of counter irritation is thought necessary, line-firing with the actual cautery is the remedy _par excellence_.

After-care.--In the course of three or four weeks subjects may be allowed the run of a paddock and, after a complete rest of six weeks at pasture, they may be returned to work with care, if the work is not of a nature to occasion concussion or other manner of irritation to the articulation.

Neurectomy is not indicated even though there is a recurrence of lameness, unless the lameness is not pronounced and inflammation is periarticular and no osseous enlargements mechanically interfere with function of the joint. There are few cases then, where neurectomy is materially helpful.

Ossification of the Cartilages of the Third Phalanx. (Ossification of the Lateral Cartilages.)

Anatomy and Function of the Cartilages.--Surmounting each wing of the distal phalanx (os pedis) is the irregularly-quadrangular cartilage. The superior border of this cartilage is thin, generally convex, and perforated for vessels to pass to the frog; the inferior border is attached to the wing of the third phalanx and posteriorly, it is reflected inward and is continuous with the inferior surface of the sensitive frog. The anterior border which is directed obliquely downward and backward becomes blended with the anterior lateral ligament of the coffin joint. The fibrous expansion of the anterior digital extensor (extensor pedis) is united to the anterior borders of the lateral cartilages.

According to Smith[27]: These structures form an elastic wall to
the sensitive foot, and attachment to the vascular laminae; they
also admit of increase in width occurring at the posterior part of
the foot without destroying the union of the two set of leaves.
Further, by their connection with the vascular system of the foot,
their elastic movements materially assist the circulation. The
primary use of the lateral cartilages is to render the internal
foot elastic, and admit of its change in shape which occurs under
the influence of the weight of the body. The alteration in the
shape of the foot is brought about by pressure on the pad, which
widens and in consequence presses on the bars. The pressure
received by the pad is also transmitted to the plantar cushion,
which likewise flattens and spreads under pressure. Both of these
factors force the cartilages slightly outwards. When the posterior
wall recoils the cartilages are carried back to their original
position. Should the elastic cartilage under pathological
conditions become converted into bone, its functions are destroyed,
and lameness may occur.

Etiology and Occurrence.--The causes of ossification of these cartilages are several. No doubt there exists a predisposition to this condition for it is of such frequent occurrence in heavy draft types of horses. Concussion plays an important rôle and, according to Möller's[28] theory, which is sound, high heel calks prevent the frog from contacting the ground, and as weight is placed upon the foot "the lateral cartilages are subjected to a continuous inward and downward dragging strain."

The condition affects the cartilages of the fore feet more frequently than those of the hind and the outer cartilage is more often ossified than is the inner. This fact may be accounted for by its more exposed position; it is also frequently injured by being trampled upon and otherwise contused or cut, as in lacerated wounds of the quarter.

Symptomatology.--Ossification of the cartilages is known by grasping the free borders with the fingers and attempting their flexion; the rigid inflexible ossified cartilage is thus easily recognized.

Lameness during weight-bearing occurs in the majority of cases at some time. Much depends on the conformation of the foot and whether the involvement affects one or both cartilages as to the degree and duration of lameness which marks this affection. In narrow and contracted heels it is reasonable to expect more lameness than in well formed feet. Where only one cartilage is ossified, the other being flexible, there is less inconvenience experienced by the subject during weight-bearing, because of the expansion of the heel which the one normal cartilage allows.

Treatment.--There is little if anything to be done in case the cartilage has become ossified except to shoe without high calks but preferably with rubber pads. The hoof should be kept moist; the wall at the quarter may be rasped thin and kept anointed. Firing is of no practical benefit in these cases, and it is doubtful if vesication is helpful excepting where only a part of the cartilage is ossified.

Subjects which continue somewhat lame, because of complete ossification of both cartilages, are best put to slow work on soft ground and not driven on pavements.

Navicular Disease.

This more or less ambiguous term has been applied to various diseases affecting the structures which make up the coffin joint. We consider this name to be applicable to inflammatory involvement of the third sesamoid (navicular bone), the deep flexor tendon (perforans) and the bursa podotrochlearis or navicular bursa.

Etiology and Occurrence.--In 1864 Thomas Greaves[29] wrote on the subject of navicular disease as follows: "The opinion I entertain upon the subject of navicular disease is, that in by far the greater majority (if not all) of these cases there exists in the animal affected a congenital tendency or predisposition, that, generally speaking, it is the high stepper, the good goer, that becomes the victim to this disease; and it is a fact well attested, that it as frequently develops itself in the feet with wide frogs, bulbous heels, shallow heels, spread flattish feet, as in the narrow upright feet.... I have known foals, born from defective parents, in which this condition was so strongly developed, that all men would at once pronounce them affected with navicular disease, and such lameness was permanent."

Often both fore feet are affected and this would point toward its being a disease wherein either conformation or congenital tendencies exists. It is rare that hind feet are involved.

There are many theories regarding the possible exciting causes of navicular disease and, when one has carefully considered the explanations as offered by Peters, Möller, Branell, Schrader and others, he may conclude that navicular disease is a non-infectuous inflammatory affection of the third sesamoid (navicular) bone, deep flexor tendon (perforans) and adjoining structures. Whether it originates in the flexor tendon or whether the bone is the original part affected, the disease is frequently met, and of all possible causes, jars and irritation incident to concussion of travel, are probably the principal causative agents.

Symptomatology.--Lameness is the primary indicator and a constant symptom which attends navicular disease wherever much structural change affects the infirm parts. As the degree of intensity or extent varies, so is there a dissimilarity in the character of the impediment. Incipient cases of bilateral involvement are more difficult to diagnose than are unilateral affections, particularly when lameness is not marked. There is manifested a supporting-leg-lameness which varies as to degree in the same subject at different times. This may be noticed during the same trip in an animal that is being driven. There is a tendency for the subject to stumble and, of course, where the affection is bilateral, there is a stilted gait owing to shortened strides.

At rest the lame animal usually points with the affected member. Because of the fact that the distance is lessened between the origin and insertion of the deep flexor tendon (perforans) by this attitude, one may readily understand the reason for the position assumed by the subject. Pressure on the navicular bone is diminished and tension on the flexor tendon is relieved by even slight volar flexion.

In acute inflammatory affections abnormal heat may be detected in the region of the heel. By exerting tension on the flexor tendon, by means of passive dorsal flexion of the member, evidence of hyperesthesia may be detected. With the hoof testers one may determine supersensitivenss in most instances. There occurs more or less contraction of the hoof in navicular disease, but this is not to be taken as a cause of the affection, but rather a sequence.

In some cases of unilateral navicular disease there is a marked contrast in size between the sound and unsound foot. However, one must not be misguided in this particular, for in some pairs of sound feet there exists considerable difference in size. Finally, by a change from the normal position of the foot to one in which the heel is somewhat elevated (as may be obtained by shoeing with high heel calks), relief is evident, and in the opposite position, the condition is aggravated. This experiment may be used for diagnostic purposes.

Treatment.--When the anatomy of the diseased parts is taken into consideration, and an analysis of the lesions which occur in cases where considerable structural change is occasioned by this affection, it is obvious that recovery is impossible. Only in cases where the inflammation is promptly checked before damage has been done the navicular bone or the flexor tendon, is permanent recovery possible. The disease is not frequently treated during this stage, however, and in the majority of instances the condition becomes chronic.

As soon as a diagnosis is made the shoes must be removed, the toe shortened with the hoof pincers and rasp and the subject is put in a well bedded box-stall. If the animal is very lame and the inflammation is acute, ice-cold packs should be applied to the feet. As soon as acute inflammation has subsided the foot may be so pared that all excess of sole and frog is removed without lowering the heels, and the animal may be blistered about the coronet region. The subject may be shod later, with heel calks that raise the heel moderately and a protracted period of rest should be enforced.

In cases where no acute inflammatory condition exists, neurectomy is beneficial. One must discriminate, however, between favorable and unfavorable subjects. This is not a last resort expedient to be employed in cases where extensive lesions of the navicular structures exists. With proper shoeing, and by putting the subject at suitable work, where concussion of fast travel on hard roads is not necessary, the best results are obtainable.

Laminitis.

This disease is primarily a non-infective inflammation of the sensitive laminae which very frequently affects the front feet. Often all four feet are affected, less frequently one foot (when its fellow is unable to sustain weight) and rarely the hind feet alone.

Occurrence.--Probably a greater number of cases of laminitis occur in localities where horses that are worked on heavy transfer wagons are, when in a state of perspiration, allowed to stand exposed to sudden lowering of temperature and to stand in a cool or cold shower of rain such as occurs near the coast of the Great Lakes or the ocean in some parts of this country.

This disease occurs in connection with digestive disorders of various kinds and, because of the frequent association of the two conditions, the common term "founder" has long been employed to designate laminitis. In cases of "over-loading," particularly when a large quantity of wheat has been eaten by animals that are unaccustomed to this diet, laminitis almost constantly results.

Large draughts of cold water, when drunk by animals that are overheated is often followed by laminitis. Concussion, such as attends hard driving, especially in unshod horses or on rough and hard roads, is often succeeded by this affection. Likewise, as has been stated, injury such as is occasioned by long continued standing on the same foot is followed by laminitis. Some horses that are frequently shod, suffer from this affection a few hours after shoes have been reset. Dr. Chas. R. Treadway of Kansas City reports the rather frequent occurrence of such conditions in horses that are in the fire department service in his city.

Age in no way influences the occurrence of laminitis and the general condition of an animal with regard to its vigor or state of flesh has no apparent influence toward predisposing horses to this ailment.

Etiology and Classification.--As it is with some other diseases, one may unprofitably theorize on cause and readily enumerate many conditions which are apparently contributory toward producing the affection. Causes may well be grouped, however, and a more definite understanding of laminitis is possible as a result. Such collocation would include conditions which directly or indirectly affect the digestion, such as puerperal laminitis, drinking of large quantities of cold water and exposure to cold and rain when the body is warm. All of these various conditions might be said to affect the vaso-constrictor nerves in such manner that the natural tendency (because of the peculiar structure of the sensitive laminae and their mode of attachment to the non-sensitive wall) which solipeds have for this affection is indirectly due to this one cause--vaso-constriction. According to Dr. D.M. Campbell, the effect of toxic materials, which may be absorbed from the digestive tract or the uterus in parturient females, upon the vaso-constrictor nerves, is such that a passive congestion of the sensitive laminae occurs and laminitis is the result. He believes that even the chilling of the surface of the body when very warm, by a cold rain, constitutes a condition wherein the effect upon the vaso-constrictors is the same.

This grouping does not include the effect of direct injuries of any and all kinds to which the feet are subjected such as: Concussion in fast road work, injuries occasioned by tight or ill fitting shoes, contusions of any kind resulting in non-infectious inflammation of the sensitive laminae, as well as the causes which produce laminitis where weight is borne by one foot when its fellow is out of function.

A classification which is practical is that of _acute_ and _chronic_ laminitis. To the practicing veterinarian it is this manner of consideration that is essential in the handling of these cases.

Symptomatology.--In the acute attack the condition is so well described by Dr. R.C. Moore[30] that we quote him in part as follows:

The acute form is generally ushered in very suddenly. Often a horse
that is perfectly free from symptoms of the disease is found a few
hours later so stiff and sore that he will scarcely move. They
stand like they were riveted to the ground. If forced to move the
evidence of pain subsides to some extent after they have gone a
short distance, to return more severe than ever after they have
been allowed to stand for a short time. If the disease is confined
to the two front feet, the hind feet are placed well under the
center of the body to support the weight and the front ones are
advanced in front of a perpendicular line so as to lessen the
weight they must bear. If they are made to move, the same position
of the feet is maintained. If made to turn in a small circle, they
do so by using the hind feet as a pivot, bringing the front parts
around by placing as little weight on them as possible.

Placing the hind feet so far under the body, arches the back and
often leads to errors in diagnosis, the condition sometimes being
taken for diseases of the loins or kidneys.

If all four feet are involved, the animal stands in the usual
position assumed in health, but if urged to move, the least effort
to do so usually brings on chronic spasms of the entire body. In
very severe cases, a slight touch of the hand will develop the
spasms. At times they are so severe, and have such short
intermissions, that the disease has been mistaken for tetanus.
However, the clonic nature of the spasm should prevent such an
error. If they are lying down, it is difficult to get them to
arise, and if they do so, they show marked symptoms of pain for
some time after rising.

If the disease is confined to the hind feet, they are placed well
forward to relieve the strain on the toe caused by the downward
pull of the perforans (deep flexor) tendon, but in place of the
front feet being kept in front of a perpendicular line, as they are
when the disease is confined to the front ones, they are placed far
back under the body, so they will carry the maximum share of the
body weight of which they are capable. The position of the feet is
of great importance and offers symptoms that should not be
overlooked.

When the subject is caused to walk, symptoms of excruciating pain are manifested in all acute cases of laminitis. In some cases where all four feet are affected, no reasonable amount of persuasion will cause the suffering animal to move from its tracks.

There is acceleration of the rate of heart action; the pulse is full and in some cases, bounding. As the affection progresses the pulse becomes rather weak and irregular. The character of the pulse in the region of the extremity is a reliable indicator; but one has to learn to make necessary discrimination because of the condition of the parts, as in some cases of lymphangitis or where the skin is abnormally thick. The characteristic throbbing pulse is, however, easily recognized in most cases. Temperature is variable, though usually elevated from one to four degrees above normal. This symptom varies with the type and stage of the affection. In a subject that has been down, unable to rise for several days, where there is a suppurative and sloughing condition of the laminae, the temperature is high. Whereas, in some other and less destructive cases there may be little thermic disturbance after the first few hours have lapsed.

A constant symptom in bilateral affections of acute laminitis is the difficulty with which the subject supports weight with one foot. It is this which causes the victim to stand as if "rooted to the ground" when all four feet are involved. If one attempts to take up one foot, thus causing the subject to stand on the other, there is much resistance and in many cases the animal refuses to give the foot.

When we consider that the sensitive parts of the foot are encased by a horny, unyielding box and that, when the laminae are congested, a great pressure is brought to bear upon the sensitive structures, it is easy to understand why the condition is so painful.

_Chronic laminitis_ is a sequel of acute inflammation of the sensitive laminae. It varies as to intensity and the exact manner of its manifestation depends upon preëxisting disturbances.

In some mild cases of laminitis there are recurrent attacks wherein no particular structural change exists, and diagnosis is established chiefly by noting the character of the pulse at the bifurcation of the large metacarpal (or metatarsal) artery just above the fetlock. The same manifestation of pain is present when weight is supported by one foot, though in a lesser degree. There is less local heat to be detected by palpation than in the acute cases.

Chronic laminitis as it occurs following acute attacks which have resulted in structural changes of the foot, present the same symptoms just described and, in addition, the peculiar alterations in structure exist. When, owing to acute inflammation of the sensitive laminae, there has resulted necrosis of this sensitive tissue together with infiltration between the anterior surface of the distal phalanx (os pedis) and the contacting hoof, the lower portion of the distal phalanx is turned downward and backward (rotated upon its transverse axis). Because of the traction which is exerted by the deep flexor tendon (perforans), as it attaches to the solar surface of the distal phalanx, this rotation is facilitated. With hyperplasia of lamina, at the anterior portion of the distal phalanx, there results a thick "white line." Rotation of the distal phalanx necessitates a descent of its apical portion and there occurs a "dropped sole."

In time, partly because of excessive wear of hoof at the heel, owing to an altered condition in the normal antagonistic relation between the flexor and extensor tendons, the toe makes an excessive growth, and the concavity of the anterior line is accentuated owing to this abnormal length of hoof. The hoof, because of recurrent inflammatory attacks, is corrugated--elevations of horn in parallel rings are usually present.

Animals that are so affected in traveling strike the heel first and the toe is later contacted with the ground surface. Rotation of the distal phalanx upon its transverse axis produces a condition, with respect to this peculiar impediment, that is equivalent to added and excessive length of the deep flexor tendon.

Where there occurs suppuration, by careful inspection of the coronary region, one may early recognize detachment of hoof. In such cases animals remain recumbent and, while the condition is not so painful at this stage, the practitioner must not overlook the real state of affairs. History, if obtainable, will be a helpful guide in such cases. Separation of hoof occurs as a rule in from four to ten days after the initial attack of acute laminitis. Needless to say these cases are hopeless, when the economic phase of handling subjects is considered.

Treatment.--Much depends upon the concomitant disturbances (or causes if one is justified in referring to them as such) as to the manner in which laminitis is to be treated. In all cases where digestive disturbances exist, the prompt unloading of the contents of the alimentary canal is certainly indicated. D.M. Campbell[31] in a discussion of laminitis has the following to say regarding the treatment of such cases:

Because superpurgation may be followed by laminitis, the
advisability of using the active hypodermic cathartics is
questioned. Neither arecolin nor eserin can cause superpurgation.
The action of the former does not continue longer than an hour
after administration and of the latter not more than eight hours.
The action of either is mild after the first few minutes.

I do not think that anyone has recommended either arecolin or
eserin where there is severe purgation. Where the intestinal canal
is fairly well emptied and its contents fluid, I should be inclined
to rely upon intestinal antiseptics to hold in check harmful
bacterial growth.

The use of alum in the treatment of laminitis is held to be without
reason other than the empirical one that it is beneficial. If
laminitis is due chiefly to an autointoxication, good and
sufficient reason for the administration of alum can be shown based
upon its known physiological action. It is the most powerful
intestinal astringent that I know of and has the fewest
disadvantages. I have not noted constipation following its use nor
diarrhea, nor a stopping of peristalsis, nor indigestion, and in
any case its action lasts at most only a few hours, and if it did
all these, it could not much matter. Quitman says, that it
constricts the capillaries. If this is true, a thing of which I am
not certain, is it not reasonable to suppose that as with other
vaso-constrictors, e.g., digitalis, there is a selective action on
the part of the capillaries (not of the drug) and those that need
it most, i.e., those of the affected feet in laminitis, are
constricted most? All body cells exert this selective action in the
assimilation of food, the tissue needing most any particular kind
of food circulating in the blood, gets it.

Our first consideration in laminitis should be to remove the
cause--to stop the absorption of the toxin in the intestinal tract
that is producing the condition. This we accomplish by partially
unloading it by the use of the active hypodermic cathartics and
stopping absorption by the surest and most harmless of intestinal
astringents. Whether the astonishingly prompt and certain action of
alum in this case is due wholly to its astringent action or whether
alum combines with the harmful bacterial products chemically and
forms an innocuous combination, I can only surmise, and it is
unimportant. At any rate, when alum is administered, the onslaught
of the disease is promptly stopped. Irreparable damage may already
have been done if the case is a neglected one, but whether
administered early or late in acute attacks, the progress of the
disease is stopped immediately.

The same authority may be profitably quoted in the matter of handling all cases wherein the revulsive effect of agents which diminish vascular tension are chiefly indicated or necessary as adjuvants. In this connection, Campbell says:

The early and vigorous administration of aconitin in laminitis to
its full physiological effect, is more logical. Assuming that
laminitis is due to absorption of harmful products from the
intestinal tract permitted through the deranged functioning of the
organs of digestion, or assuming that it is due to an extension of
the inflammation from the mucosa to the sensitive lamina, or that
it is a reflex from a sudden chilling of the skin, we have in any
of these conditions a disturbed circulation, and aconitin is the
first and foremost of circulation "equalizers." Furthermore, in
laminitis there is an elevation of the temperature, an almost
invariable indication for aconitin. A speedy return of the
temperature to normal, a very marked diminution of the pain and
improved conditions generally, appear coincident with the symptoms
of full physiological effect of aconitin when given in cases of
laminitis, which constitutes assuredly an important part of its
treatment.

Where lameness is not great as in cases wherein no marked structural change of the foot has occurred, proper shoeing is very beneficial. By keeping the heels as low as possible and shoeing without heel calks a more comfortable position is made possible. Thin rubber pads which do not elevate the heel are of service in diminishing concussion.

Dr. David W. Cochran of New York City has attained unusual success in cases of chronic laminitis with dropped sole by the use of a specially designed shoe.

Cochran claims that, not only are horses with dropped soles that would otherwise have to be put off the streets enabled to do a fair amount of work by means of this shoe, but that continually wearing it, meanwhile keeping the convexity of the front of the hoof rasped thin, in time brings about a marked improvement, and that after some months or years of use the animals are able to work with ordinary rubber-pad shoes, provided they are arranged to facilitate breaking over.

From having been successfully used on some race horses of high value, the Cochran shoe has attained considerable notoriety and is being used by a number of practitioners. A disadvantage, however, arises from the fact that few horseshoers other than Doctor Cochran seem able to make the shoe, the peculiar shape of which offers considerable difficulty in forging. Concerning the application of the shoe Cochran[32] says:

"The most important primary procedure is the preparation of the
foot to receive the shoe. All excess of growth must be removed from
the anterior face of the hoof. The outer face must be reduced at
the toe (not shortened), but rasped down thin for the lighter the
top of the foot is, the more chance the sole and coffin bone will
have of resuming their former normal position. The pressure of the
wall at the toe upon the exudate between wall and coffin bone,
tends to force the coffin bone and sole out of their normal
position. Leave the sole alone. You can lower the excess of growth
at the heels.

"There are many designs of shoes to relieve this condition. A great
deal depends on the judgment of the shoer to meet the conditions
presented, depending on the degree of the convexity and strength of
the sole. In some cases we use a shoe that admits of a large amount
of sole room. Again, we shoe with a shoe of wide cover. In other
cases a shoe with even pressure over the whole sole. In some cases
a high, narrow shoe, resting only on the wall, or the ordinary
plain shoe with side calks welded close to the outside edge and the
shoe dished well from these as a foundation. Then we have the air
cushion pad designed after the model of the bowl shoe."

In cases when slight and persistent lameness interferes sufficiently to prevent using an animal at any sort of work on hard roads, median neurectomy will relieve all lameness in most instances. This is a safe operation, moreover, in that no bad after effects are to be feared, even though lameness were to continue.

Calk Wounds. (Paronychia.)

Etiology and Occurrence.--Injuries of various kinds are inflicted upon the coronary region but usually they are due to the foot being trampled upon. When the foot that inflicts the injury happens to be unshod, a contusion of the injured member is occasioned, but in the majority of instances, wounds that demand attention are the result of shoe calks which have penetrated the tissues in the region of the coronary band. Often calk wounds are self-inflicted. When animals are excited and in turning crowd one another, they often perform dancing movements which frequently result in deep calk wounds of the coronet. Some horses have a habit of resting the heel of one hind foot upon the anterior coronary region of the other. While sleeping in this position, if they are suddenly awakened, the weight is abruptly shifted to the uppermost foot and the one underneath is (because of the pain attending its being wounded) quickly drawn out from under its fellow. In this way deep cuts may divide the coronary band and inflict extensive injury to the sensitive lamina as well.

An infectious type of coronary inflammation occurs in some localities during the winter months, wherein the condition is enzootic.

Symptomatology.--Depending upon the manner in which the injury has been produced, the appearance of the wound varies and likewise lameness is more or less pronounced. If the tissues are not divided and the wound is chiefly of the subsurface structures, there will not immediately occur pronounced local evidence of the existence of injury; but as soon as the lame animal is made to move, the peculiar character of the impediment (supporting-leg lameness with the affected foot kept well in advance of its normal position) directs attention to the extremity and all of the symptoms of acute inflammation are discovered.

Where a wound is inflicted which divides, in some manner, the surface structures (skin, coronary band, or the hoof wall) one's attention is at once called to the existence of the wound.

Because of the fact that there is every facility for the production of a sub-coronary and podophylous infection, these wounds should receive prompt attention. In some instances, the pastern joint is opened by calk wounds and then, of course, an infectious arthritis succeeds the injury.

Treatment.--In all contused wounds of the coronary region the parts need thorough cleansing; the hair, if long is clipped and a cataplasm is applied. Or preferably, an iodin-glycerin combination of one part of iodin to four parts of glycerin is poured on a layer of cotton, and this is confined in contact with the inflamed parts by means of a bandage.

Where normal resistance to infection obtains, the subject usually suffers no suppurative disturbance when the surface structures are not broken; and daily applications of the antiseptic lotion above referred to stimulates complete resolution. This may be expected in from four to ten days depending upon the extent of the injury.

If a calk wound has been inflicted, the adjoining surface structures are freed of hair and the parts cleansed in the usual manner, (which in wounds recently inflicted, should be done without employing quantities of water) and after painting the wound surface with tincture of iodin and saturating its depths with the same agent, the wound is cleansed, if it contains filth, by means of a small curette. By using a small and sharp curette, one is enabled to cleanse the average wound quickly and almost painlessly.

In such cases, equal parts of tincture of iodin and glycerin are employed. The wound is filled with this preparation and a quantity of it is poured upon a suitable piece of aseptic gauze or cotton and this is contacted with the wound. The extremity is carefully bandaged and this dressing is left in position for forty-eight hours unless there occurs, in the meanwhile, evidence of profuse suppuration--which is unusual.

One is to be guided as to the progress made by the degree of lameness present. If little or no lameness develops, it is reasonable to expect that infection has been checked; that the wound is dry and redressing every second day is sufficiently frequent.

Where cases progress favorably, recovery (unless infectious arthritis results) should occur in from ten days to three weeks. Where extensive sub-coronary fistulae result, either from lack of prompt or proper attention, the condition is then one requiring a radical operation to establish drainage and to disinfect if possible, the suppurating tissues.

Corns.

Etiology and Occurrence.--In horses, because of a tendency toward contraction of the heel in some subjects, together with work on hard roads and pavements, where the feet become dry and brittle, and because of neglect of the matter of shoeing, this affection is of frequent occurrence. Unshod horses are rarely affected. If conformation is faulty and too much weight is borne on the inner or the outer quarter, and the hoof wall at the quarter tends to turn inward, corns are usually present. They occur more frequently on the inner quarters of the front feet, though the outer quarters are occasionally also affected and in rare instances corns are found at the toes. They do not often affect the hind feet.

As soon as injury by pressure, such as is supposed to cause the formation of corns, is brought to bear on the sensitive sole, an extravasation of blood occurs. In time when the cause remains active, this discoloration is evident in the substance of the insensitive sole and consists in a red or yellowish spot which varies in size--this is ordinarily termed dry corn.

In some cases where infection of this extravasation of blood and serum occurs, instead of desiccation and discoloration of the insensitive parts, there is, in time, manifested a circumscribed area of destruction of the insensitive sole and the abscess may, where no provision for drainage exists, burrow between sensitive and insensitive laminae and perforate the tissues at the coronet. If the suppurative material discharges readily by way of the sole, no disturbance of the heel or quarters occurs above the hoof.

Symptomatology.--A supporting-leg-lameness characterizes this condition; and this lameness in most instances varies in degree with the amount of distress which is occasioned by pressure upon the inflamed parts. By an examination of the sole after having removed all dirt, and exposed the horny sole to view, no difficulty is encountered in locating the cause of the trouble.

Treatment.--Before suppuration has taken place and in the cases where suppuration does not occur, the horse-shoer's method of paring out the diseased tissue affords a means of temporary relief; but unless frequently done, in many cases, lameness results within about three weeks after such treatment has been given. In other instances temporary relief is not to be gotten in this manner for any great length of time or until a more rational mode of treatment becomes necessary so that the subject may experience a cessation of the inconvenience or distress.

The general plan which meets with the approval of most practitioners consists in careful leveling of the foot and removing enough of the wall and sole at the quarters to make possible frog pressure by means of a bar shoe. With frog pressure, expansion of the heel follows in time, and permanent relief is obtainable in this manner. Thinning the wall of the quarter is advocated by many practitioners and is undoubtedly beneficial in chronic cases where marked contraction has taken place. The wall must be thinned with a rasp until it is readily flexible by compressing with the thumbs.

There are instances, however, where corns and contraction of the heel have existed so long that they do not yield to treatment. Such cases are found in old light-harness or saddle-horses that have been more or less lame for years and where there exists marked contraction of the heels, rough hoof walls, and hard and atrophied frogs.

Suppurating corns require surgical attention in the way of removal of the purulent necrotic mass and making provision for drainage. Dry dressings, such as equal parts of zinc sulphate and boric acid, may be employed to pack the cavity. After the infectious condition has been controlled, and the wound is dry, the same plan of treatment is indicated that is employed in the non-suppurating corn. Ample time is allowed, however, for the surgically invaded tissues to granulate and, if the subject is to be put in service, a leather pad, under which there has been packed oakum and tar, affords good protection.

Quittor.

This name is employed to designate an infectious inflammation of the lateral cartilage and adjoining structures. The disease is characterized by a slowly progressive necrosis and by a destruction of more or less of the cartilage and by the presence of fistulous tracts.

Etiology and Occurrence.--The disease is due to the introduction of pus producing organisms into the subcoronary region of the foot under conditions which favor the retention of such contagium and extension of infection into contiguous tissues.