LAMENESS OF THE HORSE VETERINARY PRACTITIONERS' SERIES, NO. 1 TEXT

attempting to relieve the affected structures, and in each clinical picture of this kind, the trained diagnostician sees some index to the nature and source of the trouble. Further examination is rendered more effective because of this preliminary visual examination which has precluded the unnecessary annoyance of the animal by manipulating unaffected structures. It has been presupposed in the foregoing, that the one making visual examination of a lame animal for diagnostic purposes, will remember that with the normal animal the weight is borne equally well with both fore legs; and that this is done without shifting from one to the other; and that the pelvic limbs do not support the body in this manner. Normal subjects shift their weight from one hind leg to the other and the one relaxed, rests in a state of flexion with the toe on the ground and the heel raised. Examination by Palpation. In nearly every case where lameness exists an examination of the affected parts, by palpation or by digital manipulation, is necessary before an accurate conclusion may be drawn; but in making this kind of an examination one needs to exercise good judgment lest he fail to acquire a correct impression of the actual existent conditions. There is need for the diagnostician, here, as well as in other conditions where physical examination is made, to approach the subject in a manner that will not excite or disturb to the extent that the animal will, in one way or another, resist or object to the approach of the diagnostician, thereby masking the symptoms sought. The practitioner would best acquire skill as a horseman--if he is not possessed of such--and handle each individual subject in the manner calculated to best suit the temperament of the animal examined. The unbroken subject is not handled as satisfactorily as is the intelligent family horse; in the former, in some cases, little dependence is placed upon digital examination. By palpation one is enabled to recognize hyperthermia and this, _in lieu_ of dependable history, is at times sufficient evidence upon which to determine the duration of any given inflammatory affection. By comparison of different parts of the same member or with an analogous portion of another member any marked increase in the apparently normal temperature of a part at once signalizes inflammation. In this manner, in examining a case where laminitis or other inflammation of the feet is suspected, one may arrive at a fairly accurate conclusion without the employment of other means. Throbbing vessels are not always easily recognized if the subject is a victim of chronic lymphangitis. In some instances, where a moderate degree of lameness exists and cause is apparently obscure, the recognition of hyperthermia may be the deciding factor in establishing a diagnosis. In cases of sprained ligaments in the phalangeal region, because of the dense character of the structures involved, little if any evidence of the cause of lameness, other than local heat, may be found twenty-four hours after the injury has been inflicted. In order to determine the amount or extent of hyperthermia with a fair degree of accuracy in any given case, one must make due allowance for external conditions affecting temperature; also the effect of a considerable amount of hair covering an area, as well as any possible dirt contacting the surface of the skin must be taken into account. All dirt should be removed if practicable, so that the diagnostician's palms may come as nearly in contact with the inflamed structures as possible. Then, too, the sense of touch if the operator's hands are chilled, is not dependable. In such instances the novice will need to be deliberate as to his findings--whether or not hyperthermia really exists. Such an examination is of little value where the subject's feet are wet and an examination is hurriedly made, as in cases of suspected laminitis. 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. Where pain is not so great that relaxation of parts does not occur, one can, by gently moving an extremity in various directions--as in flexion, extension and lateral motion as well as by rotation--cause to be manifested this peculiar grating,--the friction of newly broken bone. This is known as _true crepitation_. Where the subject, suffering phalangeal fracture, manifests evidence of pain due to tensing the structures about a fractured part, one may anesthetize the parts by using about two cubic centimeters of a two per cent. solution of cocain upon the plantar nerves, proximal to the fracture. It is perhaps best to deposit the cocain solution by means of two hypodermic punctures at different points along the course of each nerve, though closely situated to one another, thereby making more sure of the solution actually contacting the nerve. In some multiple fractures of the first or second phalanx this is quite necessary; otherwise, pain produced by passive manipulation causes the subject to keep the tendons so tense that crepitation may not be detected. The unnecessary infliction of pain is always to be avoided. We know as _false crepitation_ a vibrating impulse occasioned by normal contact of articular portions of bones such as in the metacarpophalangeal joint when this structure is passively moved, where the subject permits the parts to remain in a state of complete relaxation. Attempts to recognize supersensitiveness or inflammation by means of passive movement of the shoulder or hip, whether gently or forcefully, is not productive of good, in any case, in large animals. Because of the bulk and weight of parts so manipulated, as well as the resistance the subject offers even in normal cases, no accurate conclusion is to be arrived at in this manner in the average instance. Animals nearly always resist the placing of members in any position that is so unusual and uncomfortable as that which is required to materially displace the component tissues of the shoulder or hip; therefore, such practice is useless because one can not distinguish between normal resistance and flinching caused by painful sensations in injured parts. Such manipulations are practical in small animals. Observing the Character of the Gait. In order to determine the degree of lameness as well as its character, it is necessary to cause the subject which is being examined, to move in some manner. The degree of inconvenience or distress experienced by a lame animal that is being so examined is manifested by the character of the claudication; and where much pain is occasioned in locomotion there is disturbance of respiration; perspiration may be noticeable and in some instances manifestation of nervous shock are very evident--this in timid, nervous animals that anticipate being punished when approached and, consequently, make every effort possible to move when urged to do so. An animal, then, should be moved only sufficiently to cause it to exhibit the degree of lameness present in any given case, and if a marked impediment is manifested it is not necessary to cause the subject to be exerted to the extent of inflicting, in such manner, unnecessary punishment. Further or conclusive examination is made by palpation. To cause the subject to move, an assistant may simply lead the animal with a halter and compel it to walk a few steps. In this way, lameness, whether manifested during the weight-bearing period of an affected member, or when such a member is being advanced, or whether a combination of the two conditions exists, is made apparent. In the words of Dollar, one is thus enabled to recognize the existence of "supporting-leg-lameness," "swinging-leg-lameness" or "mixed lameness." When the cause of lameness is not strikingly apparent it becomes necessary to have the subject moved farther than a few steps and at different paces. Depending then, upon the character of lameness manifested, as well as upon its degree of intensity, one needs to exercise the subject in various ways, but this should not be overdone. The first thing apparent in the lame subject in action, is the lame leg. If this is not readily determinable, as in some complicated cases, the leg or legs which are at fault are to be discovered by further examination, and to do this,--word-pictures convey little that is helpful in difficult cases,--long practice is the one route by which one may become efficient; that is, by experience gained after fundamental principles in the diagnosis of lameness have been mastered. For a careful study of supporting-leg-lameness involving a fore limb, the subject is driven or led _toward_ the one making such examination. If a hind leg is to be observed, the animal is made to travel _away from_ the examiner. Where there exists swinging-leg-lameness, the subject should be caused to move past the diagnostician, so that he may get a side view of the subject while it is in motion. In every case such examinations are made to the best advantage if the practitioner can view his patient from a little distance. Here, again, a visual examination is made but this cannot be successfully executed, in difficult cases, if the practitioner is stationed at too close range. The average subject is best observed by being led, rather than being ridden, and in so doing the animal should be given moderately free rein. A close grasp on the lead may interfere somewhat with head movements. Nodding of the head with the catching up of weight by a sound member in supporting-leg-lameness of a fore leg, constitutes the chief symptom considered in detecting the lame leg. Where supporting-leg-lameness affects a hind limb the head is raised at the time weight is caught by the sound member--here the long axis of the subject's body may be likened unto a lever of the first class. The posterior part of the body, at the time weight is taken upon the sound leg, is as the long arm: the fore limbs the fulcrum, and the subject's head the weight, which is lifted. The head movements of a horse at a trot, in supporting-leg-lameness of a front leg, synchronize with the discharge of weight from a lame leg to the opposite one if sound; but in pelvic limb affections, the head is thrown or jerked upward as weight is caught by the sound member,--this peculiar nodding movement is _opposite_ in the two instances. In pacing horses, since front and hind legs of the same side are advanced at the same time, there occurs in supporting-leg-lameness, a nodding of the head with discharge of weight from the lame leg, and a dropping of the hip as weight is caught by the sound pelvic member. In observing animals that are limping, (as in supporting-leg-lameness) one notices particularly the sacro-iliac region in hind leg affections and the occipital region in lameness of the front legs. Where there exists a bilateral affection, (such as characterizes some cases of navicular disease or other affections causing supporting-leg-lameness) there occurs no nodding of the head; weight is supported for an equal length of time upon each one of the two legs, but the stride[4] is shortened. The gait, in such cases, is peculiar, animals appearing stiff and they are said, by horsemen, to have a "choppy" gait. It is desirable, in some cases, to cause an animal to move from side to side; in other instances the subject is best made to walk or trot in a circle, and if the circle be very small the animal then particularly employs the inner fore leg as a pivotal supporting member. To augment the manifestation of certain affections, it is necessary to cause the patient to walk backward, and each one of these tests of locomotion serves to point out in a more or less characteristic manner, the site of the affection which is causing lameness in different cases. Sprains or injuries of lateral ligaments of the extremities, ringbone and certain foot affections, are made manifest by a side to side movement or a pivotal movement. In fact, wherever it is possible to cause undue or unusual tension to be exerted upon an inflamed structure, manifestation of pain is the response. In an inflamed condition of the lateral side of the phalanges, unequal weight-bearing such as a rough road surface will, by virtue of the leverage which the solar surface of the foot affords, cause undue strain upon such inflamed parts, and increased lameness is evident. When an animal is made to travel in a circle, when a member affected with supporting-leg-lameness is on the inner side of the circle, lameness is accentuated because weight is borne by the lame leg for a greater length of time, the result of such circuitous manner of locomotion. In swinging-leg-lameness, on the other hand, because pain is increased at the time an affected member is being advanced, lameness is increased when the subject is made to travel in a circle, with the lame leg on the outside of a circle thus described. In supporting-leg-lameness, the transientness of the weight-bearing period upon the affected member is the determining factor in the production of lameness. This unequal period of weight-bearing upon the