856 CAUSE OF SPLINTS. 



pare in ruminants. Splints also occur on the hind limbs, and usually 

 on the outer side of the shank. Jordanus Ruffus described splints 

 as supraossa, and Solleysel distinguished five varieties of them. At 

 firs! they were regarded as secretions from the bone, and it was only 

 in the nineteenth century that their dependence on inflammation 

 of the periosteum was clearly demonstrated. The real disease, i.e., 

 the condition causing lameness, is an osteo-periostitis associated 

 with formation of enlargement. Two periods can, therefore, be 

 distinguished: the first that of inflammation; the second that of 

 complete development, in which inflammation is absent. During 

 the first, lameness is therefore very general, but disappears during 

 the second. 



The process usually starts in the periosteum or in the interosseous 

 ligament, which fixes the internal small splint bone to the cannon 

 bone. Irritation of the bone and deep layers of periosteum causes a 

 productive osteo-periostitis, and the process of splint formation is 

 completed by ossification of the newly-formed material. The size 

 of the splint depends on the extent of surface involved and the 

 duration of the inflammation and varies between that of a three- 

 penny and a five-shilling piece. The splint itself generally assumes 

 an elongated form lying parallel with the small splint bone. When 

 the inflammatory process has subsided, and the formation of the 

 splint is complete, pain and lameness generally disappear, though 

 the splint itself remains as a blemish. In many cases, however, 

 especially in young horses, severe work is again and again followed 

 by lameness, causing the disease to persist for a long time. The 

 mature enlargement gradually diminishes, sometimes by becoming 

 flattened, sometimes by the neighbouring bone becoming thickened, 

 and under certain circumstances may so far recede as to require 

 a careful examination to detect it. The late H. G. Rogers drew 

 attention to the frequent occurrence of splints on the metatarsal 

 bones, and suggested the possibility of their causing lameness. Though 

 they undoubtedly do so in some cases, as Dollar has convinced him- 

 self, the proportion of such cases is not large. 



The cause of splint formation consists in traumatic irritation of 

 the interosseous ligament, periosteum and bones. On account of 

 their almost invariably occurring on the inner side, the view was 

 once held that splints were produced by striking. Havemann was 

 the first to expose this error, and to point out the longish shape of 

 the splint, and the fact that injury of the skin is very rare. He 

 directed attention to the construction of the carpus, and especially 

 to the position of the trapezoid bone, and viewed this as a cause 



