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.
Fig. 35—Inferior (convex) surface of Cochran shoe.
Fig. 35—Inferior (convex) surface of Cochran shoe.
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.
Fig. 36—Superior surface, showing concavity or bowl, as formed by the toe and branches of the shoe, as designed by Dr. David W. Cochran.
Fig. 36—Superior surface, showing concavity or bowl, as formed by the toe and branches of the shoe, as designed by Dr. David W. Cochran.
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.
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.
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.
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.
Morbific material is introduced into the region of the lateral cartilage by means of calk wounds and other penetrant injuries of the foot. A sub-coronary abscess which, because of lack of proper care or because of virulency of the contagium or low vitality of the subject, is quite apt to result in cartilaginous affection and its perforation by necrosis follows.
Symptomatology.—Quittor is readily diagnosed on sight in many instances. Where there is dependable history or other evidence of the chronicity of an infectious inflammation of the kind, quittor is easily identified. If no positive evidence of the disease exists, by means of careful exploration of sinuses with the probe, one may distinguish between true cartilaginous quittor and superficial abscess formation that is often accompanied by hyperplasia.
Lameness depends upon the extent of the involvement as it affects the structures contiguous to the cartilage. A variable degree of lameness is manifested in different cases.
Treatment.—Two general plans of handling this disease are in vogue. One, the more popular method, consists in the injection of caustic solutions of various kinds into the fistulous openings with the object of causing sloughing of necrotic tissue and the stimulation of healthy granulation of such wounds. The other mode consists in either complete surgical removal of the cartilage or its remaining portions, or removal of the diseased parts of curettage.
When quittor has not extensively damaged the foot and the lateral cartilage is not partly ossified as it is in some old chronic cases, the complete removal of the lateral cartilage by means of the Bayer operation or a modification thereof is indicated. A complete description of the Bayer operation as well as Merillat's operation for this disease (the latter consisting in part, in the removal of diseased cartilage with the curette) are given in Volume three of Merillat's "Veterinary Surgical Operations."
Treatment by injection of caustic solutions has many advocates and because of the fact that, in many instances the condition is such that they are not desirable surgical cases and also because some animals may be put in service before treatment is completed, the injection method is popular.
The mode of treatment advocated by Joseph Hughes, M.R.C.V.S., constitutes a very successful manner of handling quittor and we can do no better than quote Dr. J.T. Seeley [33] on his manner of using this particular treatment.
Fig. 37—Hyperplasia of right fore foot, due to chronic quittor.
Fig. 37—Hyperplasia of right fore foot, due to chronic
quittor.
Preparation.—First remove the shoe, have the foot pared very thin and balanced as nicely as possible. Moreover, all loose fragments of horn must be detached and all crevices cleaned thoroughly.
Next, have the leg brushed and hair clipped from the knee or hock to the foot and scrubbed with ethereal soap and warm water, after which the foot must be scrubbed in like manner. The foot is then placed in a bichlorid bath several hours daily, for from two to five days, depending upon whether or not soreness is shown. The bichlorid solution is 1 to 1,000 strength.
On removing the horse from the bath a liberal layer of gauze is soaked in 1 to 1,000 bichlorid solution and placed so as to cover the entire foot. On discontinuing the bath, cover the foot with gauze saturated with a 1 to 1,000 bichlorid solution. This is to be covered with absorbent cotton and a gauze bandage, and over all is placed an oil cloth or silk covering. This pack is kept moist with bichloride solution for forty-eight hours. The foot is then ready for injection.
Fig. 38—Chronic quittor, left hind foot. Showing position assumed because of painfulness of the affection.
Fig. 38—Chronic quittor, left hind foot. Showing position assumed because of painfulness of the affection.
Preparation of the Injection Fluids.—Have on hand a pint of a one per cent aqueous solution of formaldehyd made under cleanly conditions, even to a clean bottle and cork, and a clean container when ready to use the liquid. Prepare also a bichlorid of mercury solution as follows: Hydrarg. Chlor. Corros. 3IV; Acid Hydrochlor. 3Iss.; Aqua Bulliens, Oij. This should be thoroughly triturated, and then filtered into a clean bottle, when it is ready for use.
Injection.—The patient should be laid on a table, if one is available, or cast, and the foot securely fixed. Then, with an ordinary one-ounce hard rubber syringe, with a good plunger (tried first to note whether or not any fluid works around between the barrel and the plunger), introduce one syringe full of the formaldehyd solution, then thoroughly probe the quittor to determine the number of sinuses. This done, inject each sinus. If two sinuses open on the surface, close one with cotton while filling the other so that if there is a connection the solution will come in contact with all tissues involved. Irrigate with the full pint of formaldehyd solution first, then follow with six or eight ounces of the bichlorid solution. Never probe the foot nor allow it to be tampered with except in the manner prescribed.
After-Treatment.—Put on a pack saturated with a solution of bichlorid of mercury 1 to 1,000 and let it remain two days. Remove pack, and once daily afterwards wipe off with cotton the secretion which accumulates on the outside, and apply a dry dressing or healing oil composed of phenol, camphor gum and olive oil.
When Dangerous to Inject.—Never inject a quittor in the acute stage. Never inject a quittor if considerable lameness is present. On injecting a solution of formalin, hold cotton tightly around the nozzle of the syringe, when the plunger is down, then withdraw the syringe gently and note particularly if the fluid returns through the opening; if none returns cease operations at once, as it is dangerous to proceed farther, it indicates that the sinus is not well defined and the fluid retained will cause much trouble and often the death of the patient.
Experience has taught that, if extensive destructive changes of the foot exist, the Bayer operation is not indicated. In the country, where quittors are not so frequently met as in urban practice, the Merillat operation is preferable in all cases. However, the cost of the protracted period of idleness, which convalescent surgical patients require, renders the Hughes method more satisfactory in the hands of the general practitioner, especially in the city.
Nail punctures, as herein considered, embrace all penetrant wounds of the solar surface of the horse's foot due to trampling upon street nails. This does not include accidental nail pricks occasioned in shoeing. In city practice, in some stables, these cases are of frequent occurrence; and, generally speaking, nail punctures are observed more frequently in urban horses than in animals that are kept in the country.
Occurrence and Method of Examination.—This condition, then, is a rather common cause of lameness and in no case, where cause of the claudication is not obvious, is the practitioner warranted in concluding his examination without careful search for the possible existence of nail puncture of the solar surface of the foot.
Fig. 39—Skiagraph of foot. The X-ray offers very limited possibilities in the diagnosis of lameness. The location of a ''gravel'' or a nail that had worked its way some distance from the surface, or of an abscess of some proportion, deep in the tissues, might be facilitated under some circumstances by the aid of the X-ray. Its use in the detention of fractures is very limited, owing to the difficulty encountered in getting a view from the right position—many trials being necessary in most cases. The case shown above was diagnosed clinically as incipient ringbone. The X-ray revealed no lesions. (Photo by L. Griessmann.)
Fig. 39—Skiagraph of foot. The X-ray offers very limited possibilities in the diagnosis of lameness. The location of a "gravel" or a nail that had worked its way some distance from the surface, or of an abscess of some proportion, deep in the tissues, might be facilitated under some circumstances by the aid of the X-ray. Its use in the detention of fractures is very limited, owing to the difficulty encountered in getting a view from the right position—many trials being necessary in most cases. The case shown above was diagnosed clinically as incipient ringbone. The X-ray revealed no lesions. (Photo by L. Griessmann.)
In occasional instances there co-exists an obvious cause for supporting-leg-lameness and an occult cause—a nail puncture. Where such complications are met, the practitioner is not necessarily guilty of neglect or carelessness when the nail puncture is not discovered at once, nevertheless, an examination is not complete until practically every possible cause of lameness has been located or excluded in any given case.
In a search for nail puncture it is necessary to expose to view every portion of the sole and frog in such manner that the existence of the smallest possible wound will be revealed. This necessitates removal of the shoe, if, after a preliminary examination, a puncture is not found, when there is good reason to suspect its presence. However, where it is readily possible to locate and care for a wound without removal of the shoe, allowing the shoe to remain materially facilitates retaining dressings in position and relieves the solar surface of contact with the ground. If extensive injury or infection exists, it is of course necessary to remove the shoe and leave it off. By removing a superficial portion of all of the sole and frog, thus carefully and completely exposing to view all parts of the solar surface of the foot, and with the aid of hoof-testers one is enabled to positively determine the existence of nail punctures. Because of the tendency of puncture wounds of the foot to close, and since the superficial portion of the solar structures are usually soiled, it is absolutely necessary to conduct examinations of this kind in a thorough manner.
Symtomatology.—Not all cases of nail puncture cause lameness during the course of the disturbance and in many instances no lameness is manifested for some time after the injury has been inflicted—not until infection has been the means of causing considerable inflammation of sensitive structures. Nevertheless, this lack of manifestation occurs only in cases where serious injury has not taken place and the degree of lameness is a constant and reliable indicator of the character and extent of nail punctures within twenty-four hours after injury has been inflicted.
The position assumed by the affected animal inconstantly varies with the location and nature of the injury and is not of particular importance in establishing a diagnosis. The subject may support some weight with the affected member and stand "base-wide" or "base-narrow," or no weight may be borne with the foot or the animal may point or keep the extremity in a state of volar flexion. In cases where extensive injury has been inflicted, and great pain exists, the foot is kept off the ground much of the time and it may be swung back and forth as in all painful affections of the extremity.
Nail punctures cause typical supporting-leg-lameness and in some cases certain peculiarities of locomotory impediment are worthy of notice. Punctures of the region of the heel, which directly affect or involve the deep tendon sheath, cause a type of lameness wherein pain is augmented, when dorsal flexion of the extremity occurs as well as when weight is borne. Wounds in the region of the toe of the hind feet sometimes cause the subject to carry the extremity considerably in advance of the point where it is planted and, just before placing the foot on the ground, it is carried backward a little way—ten or twelve inches.
However, diagnosis of nail puncture is based on the finding of the characteristic wound or resultant local changes.
Course and Prognosis.—The nature of the progress and the manner of termination of these cases are variable. If the coffin joint has been invaded, and a septic arthritis exists, the condition is at once grave. An open and infected tendon sheath, while not so serious, constitutes a condition which is distressing, and recovery is slow even under the most favorable conditions. Where a heavy, rigid and sharp nail enters the foot, in such manner that fracture of the third phalanx (os pedis) occurs, this complication makes for a protraction of the condition. Experience teaches that the natural course and termination in these cases are modified by the location and depth of the injury, virulency of the contagium and resistance of the subject to such infection.
Prevention.—In all horses which are kept at such work that exposure to nail punctures is frequent, a practical means of prevention of such injuries consists in the employment of heavy sole leather or suitable sheet metal to cover the sole of the foot and, at the same time, confine oakum and tar in contact with the solar surface to prevent the introduction of foreign material between the foot and such protecting appliances. Further, if drivers and owners could be impressed with the serious complications which so frequently attend wounds of this kind, undoubtedly many cases which are now lost, because of ignorance or neglect on the part of the teamsters or proprietors of horses, would be saved by prompt and rational treatment.
Treatment.—The treatment of this condition falls so largely within the dominion of surgery that we can give little more than an outline here.
In cases where there exists no evidence of open joint or open tendon sheath as judged by the site of the puncture and degree of lameness present (after having thoroughly cleansed the solar surface of the foot and enlarged the opening in the nonsensitive sole) a little phenol is introduced into the wound. In such cases, where it is possible for the antiseptic to contact every part of wound surface to the extreme depths of the puncture, infection is prevented when such treatment is promptly administered. This may be considered as first aid, or emergency care, and is indicated in all wounds of the foot whether the injury be serious or almost insignificant.
Subsequently one of two general courses may be pursued in the treatment of cases of nail puncture. One, by the employment of means to keep the wound patent and injection of suitable antiseptics, or agents that are more or less caustic in conjunction with strict observance of asepsis and wound protection. The other method consists in prompt establishment of drainage by surgical means and includes exploration and curettage.
The first method is better adapted to the use of the average general practitioner and he would do well to keep the opening in the nonsensitive structures patent. By introducing equal parts of tincture of iodin and glycerin daily, good results will follow in most instances. The wound is protected in unshod horses, either by completely bandaging the foot and retaining, in contact with the wound, cotton that is saturated with iodin and glycerin, or, if a minor injury exists, the moderately enlarged opening in the nonsensitive sole or frog, which has been moistened with the antiseptic, is packed with a very small quantity of cotton. A little practice in this mode of closing benign puncture wounds will enable the practitioner to successfully protect the sensitive parts in the treatment of such cases in unshod country horses.
When the condition progresses favorably the wound may be dressed every second day or twice weekly, and in the course of from two to six weeks recovery should be complete.
If the practitioner is somewhat proficient as a surgeon, and has at his command facilities for doing surgery, the second method is preferable in many cases. By using a local anesthetic on the plantar nerves and confining the subject on an operating table, restraint should be perfect. The solar surface of the foot is first thoroughly cleansed, the puncture wound is enlarged in the nonsensitive structures and the parts are then moistened with phenol or other suitable antiseptics. By means of a small probe the puncture is explored and, depending on the character of the wound and the structures involved, surgical intervention is varied to suit the case. If necessary, all of the insensitive frog is removed, and in wounds affecting the region of the heel the tissues may be incised from the puncture outward dividing all of the tissues outward and backward to the surface. A suitable surgical dressing is then applied.
If, on the other hand, the puncture extends into the navicular bursa, the radical operation is perhaps indicated, though not until one is sure that infection of the bursa and serious consequences are to follow if this operation is not performed. Detailed description of the technic of this operation belongs to the realm of surgery and a good discussion of it is to be found in William's work on veterinary surgical and obstetrical operations.
One may summarize the discussion of treatment of nail puncture by saying that emergency care as herein described is of first consideration. In every case an immunizing dose of anti-tetanic serum should be given. Subsequently, the method employed must suit the character of the wound, existing facilities for handling the subject and the skill and aptitude of the practitioner.
[5] Manual of Veterinary Physiology, by Major-General F. Smith, page 590.
[6] Manual of Veterinary Physiology by Major-General F. Smith, page 589.
[7] Regional Veterinary Surgery and Operative Technique, Jno. A.W. Dollar, M.R.C.V.S., F.R.S.E., M.R.I., page 765.
[8] Dr. Roscoe R. Bell in the Proceedings, N.Y. State Veterinary Medical Society, 1899.
[9] American Veterinary Review, Vol. 35, P. 456.
[10] "Radial Paralysis and Its Treatment by Mechanical Fixation of Knee and Ankle," Geo. H. Berns, D.V.S. Proceedings of the American Veterinary Medical Association, 1912, p. 219.
[11] As quoted by Berns, in Radial Paralysis, etc., Proceedings of the A.V.M.A., 1912.
[12] Veterinary Surgical Operations, by L.A. Merillat, V.S., p. 507.
[13] A paper presented before the Illinois Veterinary Medical Assn. by Dr. H. Thompson of Paxton, Ill., American Veterinary Review, Vol. 15, p. 134.
[14] "Fractures in Foals," by Dr. Wilfred Walters, M.R.C.V.S., American Journal of Veterinary Medicine, Vol. 8, p. 669.
[15] American Veterinary Review, Vol. 26, p. 1068.
[16] Fractures, by H. Thompson, Paxton, Ill., American Veterinary Review, Vol. 15, p. 134.
[17] Veterinary Surgical Operations, by L.A. Merillat, Vol. 3, p. 198.
[18] Wilfred Walters, American Journal of Veterinary Medicine, Vol. 8, p. 606.
[19] J.N. Frost, assistant professor of Surgery, Veterinary Dept., Cornell University, in "Wound Treatment," page 159.
[20] Open Joints and Their Treatment in my practice, by J.V. Lacroix, American Journal of Veterinary Medicine, Vol. 5, page 203.
[21] Regional Veterinary Surgery Möller—Dollar, page 605.
[22] Extract from Receuil de Médecine Vétérinaire in Ameircan Veterinary Review, Vol. 23, p. 893.
[23] Fracture of All the Sesamoid Bones, by R.F. Frost, M.R.C.V.S., A.V.D., Rangoon, Burmah, in American Veterinary Review, Vol. 5, p. 362.
[24] The Anatomy of the Domestic Animal, by Septimus Sisson, S.B., V.S.
[25] Traité De Thérapeutique Chirurgicale Des Animaux Domestique, par P.J. Cadiot et J. Almy, Tome Second, page 547.
[26] Anatomie Regionale Des Animaux Domestique, page 695.
[27] Manual of Veterinary Physiology, by Major-General F. Smith, C.B., C.M.G., page 678.
[28] Möller's Regional Veterinary Surgery, by Dollar, page 630.
[29] Edinburgh Veterinary Review, Vol. VI, page 616.
[30] Equine Laminitis or Pododermatitis, by R.C. Moore, D.V.S., American Journal of Veterinary Medicine, Vol. XI, page 284.
[31] American Journal of Veterinary Medicine, Vol. XI, page 318.
[32] The Shoeing of a Dropped Sole Foot by Dr. David W. Cochran, New York City, The Horse Shoers Journal, March, 1915.
[33] Quittor and Its Treatment by the Hughes Method, J.T. Seeley, M.D.C., Seattle, Washington, Chicago Veterinary College Quarterly Bulletin, Vol. 9, page 27.
The pelvic bones as a whole constitute the analogue of the scapulae with respect to their function as a part of the mechanism of locomotive and supportive apparatus of the horse. The manner of attachment or connection between the ilia and the trunk is materially different from that of the scapulae, however, and the angles as formed by the long axes of the ilia in relation to the spinal column are maintained by two functionally antagonistic structures—the sacrosciatic ligaments, and the abdominal muscles by means of the prepubian tendon. The sacro-iliac articulations are such that a very limited amount of movement is possible; free movement, however, is unnecessary because of the enarthrodial (ball and socket) femeropelvic joint.
The various muscles which exert their effect upon the pelvis in changing their relationship between the long axes of the ilia and spinal column, are concerned but little more in propulsion and weight bearing than are the pectoral muscles. A general treatise on the subject of lameness does not properly include such structures any more than it does the various affections of the dorsal, lumbar and sacral vertebrae or inflammation of the abdominal parietes. Involvement of such parts cause manifestations of lameness but the matter of establishing a diagnosis is difficult in many instances and in some cases impossible.
The femeropelvic articulation is formed by the hemispherical head of the femur and the acetabulum; the latter constituting a cotyloid cavity which is deepened by the cotyloid ligament.
The round ligament (ligamentum teres) is the principal binding structure of the hip joint and it arises in a notch in the head of the femur and is attached in the subpubic groove close to the acetabular notch. Another ligament, peculiar to Equidae—the accessory (pubiofemoral)—is attached to the head of the femur near the round ligament and passes through the cotyloid notch and along the under side of the pubis. It is inserted or blends with the prepubic tendon. This ligament prevents extreme abduction of the leg. The joint capsule encompasses the articulation and is attached to the brim of the acetabulum and the edge of the head of the femur.
Fig. 40—Sagital section of right hock. The section passes through the middle of the groove of the trochlea of the tibial tarsal bone. 1 and 2. Proximal ends of cavity of hock joint. 3. Thick part of joint capsule over which deep flexor tendon plays. 4. Fibular tarsal bone (sustentaculum). A large vein crosses the upper part of the joint capsule (in front of 1). (From Sisson's ''Anatomy of the Domestic Animals.'')
Fig. 40—Sagital section of right hock. The section passes through the middle of the groove of the trochlea of the tibial tarsal bone. 1 and 2. Proximal ends of cavity of hock joint. 3. Thick part of joint capsule over which deep flexor tendon plays. 4. Fibular tarsal bone (sustentaculum). A large vein crosses the upper part of the joint capsule (in front of 1). (From Sisson's "Anatomy of the Domestic Animals.")
Fig. 41—Muscles of right leg; front view. The greater part of the long extensor has been removed. 1, 2, 3. Stumps of patellar ligaments. 4. Tuberosity of tibia. (From Sisson's ''Anatomy of the Domestic Animals.'')
Fig. 41—Muscles of right leg; front view. The greater part of the long extensor has been removed. 1, 2, 3. Stumps of patellar ligaments. 4. Tuberosity of tibia. (From Sisson's "Anatomy of the Domestic Animals.")
The stifle joint is analagous to the knee joint of man and is to be considered an atypical ginglymus (hinge) articulation formed by the femur, tibia and patella. The ligaments are femerotibial, femeropatellar and capsular.
In addition to the usual provision for articulation of bones there are situated cartilaginous menisci between the condyles of the femur and the head of the tibia. These discs surround the tibial spine and are otherwise shaped to fit perfectly between the articular portions of the femur and tibia.
Collateral ligaments (internal and external lateral) pass from the distal end of the femur to the proximal portion of the tibia. The mesial (internal) arises from the internal condyle of the femur and is attached to a rough area below the margin of the medial (internal) condyle of the tibia. The lateral (external), shorter and thicker, arises from the depression on the lateral epicondyle and inserts to the head of the fibula.
The crucial or interosseus, anterior and posterior, are situated between the femur and tibia, and according to Smith,[34] the crucial ligaments are necessary to properly join the two bones, because of the character of the structure of the articular ends of the femur and tibia.
The femeropatella ligaments are two thin bands which reinforce the capsular ligament. They arise from the lateral aspects of the femur, just above the condyles and are inserted to the corresponding surfaces of the patella.
The patellar ligaments are three strong bands which arise from the antero-inferior surface of the patella, and are inserted to the anterior aspect of the tuberosity of the tibia.
Taken as a whole, the tarsal bones, interarticulating and articulating with the tibia and metatarsal bones form the hock joint and this articulation is analagous to the carpus. As with the carpus, there is less movement in the inferior portion of the joint than in the superior part of the articulation. The chief articulating parts are the tibia with the tibial tarsal bone (astragulus).
Fig. 42—Muscles of lower part of thigh, leg and foot; lateral view, o', Fascia lata; q, q', q'', biceps femoris; r, semitendinosus; 21', lateral condyle of tibia. The extensor brevis is visible in the angle between the long and lateral extensor tendons. (After Ellenberger-Baum, Anat. für Künstler.) (From Sisson's ''Anatomy of the Domestic Animals.'')
Fig. 42—Muscles of lower part of thigh, leg and foot; lateral view, o', Fascia lata; q, q', q", biceps femoris; r, semitendinosus; 21', lateral condyle of tibia. The extensor brevis is visible in the angle between the long and lateral extensor tendons. (After Ellenberger-Baum, Anat. für Künstler.) (From Sisson's "Anatomy of the Domestic Animals.")
The capsular ligament is attached around the margin of the articular surfaces of the tibia, to the tarsal bones, the collateral ligaments (internal and external lateral) and to the metatarsus.
Fig. 43—Right stifle joint; lateral view. The femoro-patellar capsule was filled with plaster-of-Paris and then removed after the cast was set. The femoro-tibial capsule and most of the lateral patellar ligament are removed. M. Lateral meniscus. (From Sisson's ''Anatomy of the Domestic Animals.'')
Fig. 43—Right stifle joint; lateral view. The femoro-patellar capsule was filled with plaster-of-Paris and then removed after the cast was set. The femoro-tibial capsule and most of the lateral patellar ligament are removed. M. Lateral meniscus. (From Sisson's "Anatomy of the Domestic Animals.")
The common ligaments of the tarsal joint are the collateral, the plantar (calcaneo-metatarsal and c. cuboid) and dorsal ligaments (oblique).
The medial (internal lateral) ligament serves to join the medial (internal) tibial malleolus with tibial tarsal (astragalus) and other tarsal bones.
The lateral (external lateral) ligament is inserted to the lateral (external) tibial malleolus and its distal portions are attached to the tibial tarsal (astragalus), fibular tarsal (calcaneum) bone, fourth tarsal (cuboid) and metatarsus bones.
Fig. 44—Left stifle joint; medial view. The capsules are removed. (From Sisson's ''Anatomy of the Domestic Animals.'')
Fig. 44—Left stifle joint; medial view. The capsules are removed. (From Sisson's "Anatomy of the Domestic Animals.")
The plantar ligament (calcaneo-cuboid) is a strong flat band which is attached to the plantar surface of the fibular and fourth tarsal bones (calcaneum and cuboid) and the head of the lateral metatarsal (external small) bone.
The dorsal (oblique) ligament is attached above to the distal tuberosity on the inner side of the tibia. It is inserted below to the central (cuneiform magnum) and third (c. medium) tarsal bones, to the proximal ends of the large and outer small metatarsal bones.
The tarsus is a true hinge joint and because of the great strain which it sustains, is subject to frequent injury. About seventy-five percent of cases of lameness affecting the hind leg may be said to arise from disease of the hock.
As members of locomotion the legs receive strains of two kinds: those of concussion and weight-bearing and strains of propulsion; the latter are the greater. In the horse as a work animal, the hind legs are probably subjected to greater strains than are the front but the manner of construction of the various parts of the pelvic limbs with the possible exception (according to some authorities) of the tibial tarsal joint, offsets this condition.
The femur may be considered analagous to the humerus in that it bears a similar relationship to the ilium, that exist between the humerus and scapula. Further flexion during repose is prevented chiefly by the glutens medius (maximus) muscle and its tendons. The larger tendon inserts to the summit of the trochanter major of the femur and corresponds to the biceps brachii in the action of the latter on the scapulohumeral joint, except that the gluteus medius, in attaching to the femoral trochanter, exerts its effect as a lever of the first class. Because of the relationship between the long axes of the femur and iliac shaft it is evident that the angle formed by these two bones is maintained chiefly by the gluteus muscles during weight bearing. Contraction of muscular fibers of the gluteus medius causes extension of the femur and muscular strain is prevented to a great degree by the inelastic portion of this muscle. The chief physiological antagonistics of the glutei are the quadriceps femoris and tensor fascia lata.
While the leg is supporting weight the stifle joint is fixed in position mainly by the quadriceps femoris group of muscles which are attached to the patella. Tendinous fibres intersect this muscular mass and relieve muscular strain during weight bearing. Because of the manner in which the patella functionates with the trochlea of the femur, comparatively little energy is required to prevent further flexion of the stifle joint. The patella, according to Strangeways, may be considered a sesamoid bone.
Fig. 45—Left stifle joint; front view. The capsules are removed. 1. Middle patellar ligament. 2. Stump of fascia lata. 3. Stump of common tendon of extensor longus and peroneus tertius. (From Sisson's ''Anatomy of Domestic Animals.'')
Fig. 45—Left stifle joint; front view. The capsules are removed. 1. Middle patellar ligament. 2. Stump of fascia lata. 3. Stump of common tendon of extensor longus and peroneus tertius. (From Sisson's "Anatomy of Domestic Animals.")
The quadriceps group of muscles is assisted by the anterior digital extensor (extensor pedis) peroneus tertius and tibialis anticus (flexor metatarsi) muscles. The latter pair (flexor metatarsi, muscular and tendinous portions, because of their attachment to the external condyle of the femur and to the metatarsal bone) are enabled to automatically flex the tarsal joint when the stifle is flexed.
The hock is kept fixed in position by the gastrocnemius and the superficial digital flexor (perforatus). The latter structure, which is chiefly tendinous, originates in the supracondyloid fossa of the femur and has an insertion to the summit of the fibular tarsal (calcis) bone. It relieves the gastrocnemius of muscular strain during weight bearing.
Smith[35] styles the function of the stifle and hock joints a reciprocating action, and we quote from this authority the following: