Lameness of the Horse / Veterinary Practitioners' Series, No. 1

by John Victor Lacroix

Often, before being able to distinguish the presence of a hyperthermic condition, one is impressed with the fact that an animal manifests evidence of being supersensitive. In fact, some animals in the anticipation of pain at the touch of an injured part, will instinctively withdraw—in self-protection—such an ailing member or resist the approach of the practitioner. This sensitiveness is more apparent in animals that have been subjected to previous manipulation or treatment which has occasioned pain, and consequently, allowance must be made for this exhibition of fear. No better example of this condition can be imagined than is present in cases of "shoe boil," where there exists an extensive area of acute inflammation of the elbow. There is always more or less surface disturbance wherever vesication has been produced, and in cases where irritants of any kind have been employed for several days or a week previous to an examination, more or less supersensitiveness is to be expected.

One must not lose sight of the fact that unscrupulous dealers,—"traders"—make use of their knowledge of this principle in various way usually for the purpose of attracting attention to a part, which, presumably might have been blistered in order to intentionally produce inflammation of tissues, in this way, causing lameness which is not manifested until an animal has been kept by its new owner for twenty-four hours or more. This, to be sure, usually makes a dissatisfied purchaser who is willing to dispose of his newly acquired animal at a sacrifice, thus enabling the original owner or his agent to regain possession of the victimized animal at less than its real value.

Some nervous animals, because of the manner of approach of the practitioner, are wont to flinch, and there is manifested a pseudo-supersensitiveness. Young animals not accustomed to being handled are likely to be timorous, and one must not hastily conclude that a part is painful to the touch because the subject resents even gentle digital manipulation of such parts. In instances of this kind, one needs to compare sensibility by manipulation of different parts of the subject's body in a careful and gentle manner; and by exercising patience and good judgment in such work, it is possible to actually distinguish between normal sensibility and abnormal sensitiveness, in most cases. Here, again, the diagnostician needs to possess skill as a horseman and good judgment as to individual temperament of different animals, under any condition which may exist at the time he makes his examination.

By palpation alone, one can recognize the presence of fluctuating enlargements; one may not only recognize such conditions, but distinguish between a fluctuating mass such as exists in non-strangulated hernia and a large fibrous tumor. By palpation, for the recognition of density and for determining the presence or absence of hyperthermia, one may decide that there exists an abscess and not a tumor. Edematous swellings are recognized by palpation,—the characteristic indentations which may be made in dropsical swellings are pathognomonic indicators. In this manner it is easy to differentiate post-operative or post-traumatic edemas which may or may not cause lameness. At any rate, it is essential to take into account all determinate conditions that may assist in the prognosis of any given case, for the purpose of being able to outline rational remedial measures. To be able to distinguish between the generalization of a septic infection in its incipiency, and a more or less benign edema, is largely possible by digital manipulation alone. An extremity may be greatly swollen because of the existence of chronic lymphangitis, influenza, or an acute septic infection occasioned by the introduction of pathogenic and aerogenic organisms. Since the effect produced by these dissimilar ailments are productive of conditions that may terminate favorably or unfavorably, it becomes necessary for the diagnostician to develop a trained, discriminating, tactile-digital sense, in order to correctly interpret existing conditions, and handle cases in a rational and skillful manner.

In order to ascertain the extent and exact location of a tumor, an exostosis, or other enlargements, the diagnostician, here also, needs to be in possession of a trained tactile sense and in addition if he be fortified with an accurate knowledge of normal anatomy and pathology, he is able to arrive at proper conclusions, when digital manipulations have been employed. Fibrous tumors are sometimes located in the inferior part of the medial side of the tarsus—exactly over the seat of bone-spavin. Such tumors, when the affected member is supporting weight, are not to be distinguished from exostoses; but as soon as the affected leg ceases to bear weight, it may be passively flexed and the nature of the enlargement recognized because it may be slightly displaced by digital manipulation. Displacement, of course, is not possible with an exostosis.

A necessary qualification, which the diagnostician must possess, is that of being able to judge carefully the nearness of any given exostosis to articular structures. Also, the extent or area of the base of an exostosis as well as its exact position, needs be determined before one may estimate the probable outcome in any case,—whether treatment should be encouraged or discouraged by the practitioner. Periarticular ringbone may, because of the size and location of the exostosis, constitute a condition which cannot be relieved in any way in one case, and in another, because of the manner of distribution of such osseous deposits, the condition may be such that prompt recovery will follow proper treatment. In the examination of an exostosis of the tarsus, it is particularly important to determine the exact location of the exostosis—whether or not the spavin involves the tibial tarsal (astragulus) bone very near its tibial articular portions. Obviously, if articular surfaces of joints are involved, complete recovery cannot result despite the most skillful attention given the subject.

Passive Movements.

Wherever it is possible to gain the confidence of a tractable animal to the extent that it will relax the structures sufficiently to make possible passive movement of affected parts, much is to be learned as a result of such manipulation. By this method one may differentiate true crepitation, false crepitation, luxation and inflammation of ligaments that have been injured, as in sprains of such structures in the phalangeal region.

True crepitation is recognizable by the characteristic vibration which is interpreted by tactile sense. It is possible to recognize fracture by the use of other methods—auscultation, tuning fork tests, etc., but in ordinary veterinary practice one must rely upon the sense of touch for recognition of crepitation.