DISEASES OF 



dition of new bone formation between other bones oc- 

 cur in any part of the hock joint. Sometimes its ex- 

 tension from the point of beginning 1 to other bones in 

 the joint is extremely slow. "We can also have this bony 

 material thrown out between any two of the bones, and 

 as can be readily understood, without any extra en- 

 largement outside of the joint. We may, in fact, have 

 severe and long-continued lameness from inflammation 

 or ulceration occuring all through the joint between 

 the various bones, and yet have no external enlarge- 

 ment. This, then, is why there is such a variety of 

 opinion on the subject of the presence or absence of 

 spavin iu horses that are lame in the hind limb. I 

 have made a dissection in which all the bones entering 

 into the formation of the hock joint were joined togeth- 

 er as if in one bone, and in which there was only a 

 small amount of enlargement on the surface of the 

 bones where the so-called spavin is usually situated. 

 In this place we shall call all cases spavin where there 

 is an inflammation, or its results (which usually lead to 

 a new bony formation) in any part of the hock joint, 

 whether there is an enlargement on the surface of the 

 bones or not. It can now be seen that the enlargement 

 is apt to occur on almost any part of the surface of the 

 bones of the hock. It is found, however, that in most 

 cases the new growth is situated on the inside of the 

 hock ; very rarely on the outside. This is accounted 

 for by the inside of the limb being more under the cen- 

 tre of gravity, and apparently having to take more of 

 the concussion than the outside. Probably for the 

 same reason the front of the inside is more frequently 

 the subject of spavin than is the surface toward the 



