Lameness of the Horse | Page 6

the impact has been sufficiently violent, the portion becomes an amorphous mass.
In a treatise on the subject of lameness, the bones chiefly concerned and most often affected must be especially considered. The shape and size of a bone when injured, determines in a measure, the course and probable outcome in most cases, but of first and greater importance is the function of the bone. A fracture of the fibula in the horse need not incapacitate the subject, but a tibial fracture is serious and generally proves cause for fatal termination. The body of the scapula may be completely fractured and recovery will probably result in most cases without much attention being given to the subject, yet a fracture of the neck of this same bone constitutes an injury of serious consequence. The difference in the function of different parts of this same bone, as well as its shape and mode of attachment, determine the gravity of the case; so it is in fractures of other bones with respect to the course and prognosis of the case--function is the important factor to be considered.
Next in importance is the age of the animal suffering fracture of the bone. Capacity for regeneration is naturally greater in a vigorous, young animal than in aged or even middle-aged subjects. A healthy condition of the bone and the body favor the process of repair in case of fracture, and prognosis may be favorable or unfavorable, depending upon these factors mentioned for consideration. Individuals of the same species, differing in temperament, may comport themselves in a manner that is conductive to prompt recovery, or to early destruction. This feature cannot be overestimated in importance, as it is sometimes a decisive element, regardless of other conditions. A horse suffering from an otherwise remediable pelvic fracture may be so worried and tortured by being confined in a sling that the case calls for special attention and care because of the animal's temperament. Sometimes, the constant presence of a kind attendant will so reassure the subject that it will become resigned to unnatural confinement, in a day or two. This precaution may, in itself, determine the outcome, and the wise veterinarian will not overlook this feature or fail to deviate from the usual rote in the handling of average cases. Recovery may be brought about in irritable subjects by this concession to the individual idiosyncrasies of such animals.
AFFECTIONS OF LIGAMENTS.
Ligaments which have to do with the locomotory apparatus are, for the most part, inelastic structures which are composed of white fibrous tissue and serve to join together the articular ends of bones; to bind down tendons; and to act as sheathes or grooves through which tendons pass, and as capsular membranes for retention of synovia in contact with articular surfaces of bones.
Ligaments are injured less frequently than are bones. Because of their flexibility they escape fracture in the manner that bones suffer. They are, however, completely severed by being cut or ruptured, though fibrillary fracture the result of constant or intermittent tensile strain is of more frequent occurrence.
Simple inflammation of ligaments is of occasional occurrence but, unless considerable injury is done this tissue, no perceptible manifestation of injury results. No doubt many cases wherein fibrillary fracture of ligaments (sprain) takes place some lameness is caused, but because of the dense, comparatively nonvascular nature of these structures, little if any manifestation, except lameness, is evident. And such cases, if recognized are usually diagnosed by excluding the existence of other possible causes and conditions which might also cause lameness.
Certain ligaments are subjected to strain more than are others and therefore, when so involved, frequently cause lameness. Examples of this kind are affections of the collateral (lateral) ligaments of the phalanges. Because of the leverage afforded by the transverse diameter of the foot, when an animal is made to travel over uneven road surfaces, considerable strain is brought to bear on the collateral ligaments of the phalanges. A sequel to this form of injury is a circumscribed periostitis at the site of attachment of the ligaments and frequently the formation of an exostosis--ringbone--results.
Where sudden and violent strain is placed upon a ligament and rupture occurs, the division is usually effected by the ligament being torn from its attachment to the bone. In such cases, a portion of periosteum and bone is usually detached and the condition may then properly be called one of fracture. In some cases of this kind recovery is tardy, because of the difficulty in maintaining perfect apposition of the divided structures, and reactionary inflammation is not of sufficient extent to enhance prompt repair. In fact, some cases of this kind seem to progress more favorably, when no attempt at immobilization of the affected member is attempted.
If some freedom of movement is allowed, acute inflammation resulting in nature's provisional swelling