SPLINTS 507 



jarring tlioir limbs in a greater degree, but also from the more spongy and 

 open texture of their bones which admit of the pressui-e of large blood- 

 vessels within them, and are thus more liable to congestion, and consequent 

 morbid secretion. Exostosis is shown in the form of splints, ringbone, 

 sidebone, or ossified lateral cartilages, spavin, as well as in the growths 

 which occur occasionally in other parts of the body which have received no 

 distinguishing name. 



Caries (ulceration) occurs as a consequence of inflammation, and in the 

 horse either results from external injury, as in poll evil and fistulous withers, 

 or from mismanagement, or heredity as in navicular disease, which latter 

 affection will be considered under the diseases of the foot. It is always 

 attended with pain, and in severe cases with the formation of sufficient 

 matter to require an outlet, but in very restricted ulcerations, such as occur 

 in navicular disease, the pus passes into the joint, and is reabsorbed with 

 the synovia. 



ANcnvLosis, when it is the result of caries in the two adjacent surfaces 

 of a joint, produces union between them, but in the horse it is generally of 

 a secondary kind, the result of bony growths (exostosis) thrown out from 

 the surfaces of the two bones near the joint, which, coalescing, unite into 

 one mass, and thus destroy all motion. 



SPLINTS 



The strict, definition of this disease is "an exostosis from the lower 

 part of the small metacarpal bone, connecting it by bony union with the 

 large metacarpal bone," but among horsemen, any bony growth from the 

 cannon-bone is considered a splint, and the latter is almost as common as 

 the former. The regular splint rarely attacks the outer small metacarpal 

 bone alone, but sometimes in very bad cases both are implicated in the 

 disease, a specimen of which is given in Fig. 92, on next page. It is 

 difficult to give a valid reason for this greater frequency of splint on the 

 inside than on the out, but it is commonly said that the inner splint-bone 

 receives more of the weight of the body than the outer one, and that it is 

 more under the centre of gravity, but as it is merely suspended from the 

 carpus, and is not supported from below (in any way, mediately or directly), 

 this can produce no injurious effect upon it. The fact is so, however, 

 whatever may be the cause. 



The S'ympfoins of splint are generally a greater or less degree of lameness 

 during its formation, but sometimes it may go on to attain a large size without 

 any such result, especially if its growth is slow, and the horse is not severely 

 worked. While the periosteum or membrane covering the bone is inflamed 

 and stretched, much lameness is often present, but when the first inflam- 

 matory action subsides the animal may go sound again. Thus we find a 

 young horse come out sound and fall lame on the journey when splint is the 

 cause, while a foot lameness may be marked on the starting, but pass off on 

 the road with the increased circulation of the blood, and additional secretion 

 of synovia or joint oil. A night's rest and a cold bandage may appear to 

 restore the animal to soundness, but on being put to work or even moderate 

 exercise the lameness will often recur. Though splints or exostoses which 



