18 LAMENESS IN THE HORSE. 



Ill the latter one looks for muscular atrophy, but this 

 symptom must not be credited immediately as the seat of 

 lameness, since in all chronic or severe forms of lameness 

 atrophied muscles may be expected ; but atrophy of certain 

 groups of muscles, especially the antea and postea spinatus, 

 or the olecranian muscles, justly hints at the seat of 

 lameness. 



The examination of the hind-leg does not differ mate- 

 rially from that of the fore-leg. The inner surface of the 

 hock requires close attention, a thorough knowledge of the 

 anatomy of that region, a good deal of practice and 

 discretion whenever an attempt is made to locate a spavin, 

 and it is essential that the observer takes the same position 

 in viewing and comparing the contour of both hocks. 



First, the anterior part of the inner surface of the tarsus 

 is viewed by standing a little to one side of the fore-leg; 

 then, by sighting the hock from between both fore-legs, the 

 middle of the internal hock surface can be criticised, the 

 posterior portion of the internal face of the hock being 

 looked at from behind. 



Sometimes the length or roughness of the hair interferes 

 with the recognition of the contour of the joint ; then the 

 hair should be moistened to make it lie close to the skin. 

 Horses with sickle-shaped hocks may mislead the observer, 

 as the bones at the inner and posterior part of the hock are 

 naturally enlarged ; at the same time, in some horses one 

 particular bone may be enlarged, and if the same bone 

 is equally large in the other hock, spavin cannot be 

 pronounced. 



The middle and lower layer of hock bones are sometimes 

 divided by distinct grooves, which give rise to ridges, and 

 the greater development of the inner metacarpal bone must 



