284 DISEASES OF THE HORSE. 



state is itself the subject of friction. The jointthen becomes 

 inflamed and ulcerated, and the lameness is often incurable. 



Bone Spavin. 



[Spavin is a deposition of bony substance on the inside of the 

 hock. It is generally produced by a strain of the ligaments 

 which confine the small bones of the hock. The lameness often 

 precedes the spavin, and sometimes gets better after its formation. 

 The effect of spavin is to join the small bones of the hock to- 

 gether, and thus to destroy the spring which the existence of 

 three joints below the astragalus is capable of affording. When 

 the spavin is situated low it only destroys the use of one joint, 

 Avhich is often compensated for by those above. The higher the 

 spavin is situated the worse it is, and sometimes it is so extensive 

 as to anchylose all the bones of the hock, leaving only the action 

 of the tibia and astragalus. The lameness from spavin or dis- 

 ease of the hock is peculiar, — the horse draws up his leg with 

 remarkable celerity, more so than in any other lameness. 



The causes of spavin are anything that distresses the liga- 

 ments of the joints, — such as hunting or severe exertion, par- 

 ticularly with young horses, and the practice sometimes adopted 

 of making the outer heel of the shoe much higher than the 

 inner. 



The treatment generally adopted is firing the part deeply, or 

 a seton may be inserted under the skin, immediately over the 

 enlargement, and continued for a month. — Ed.] Some farriers 

 employ caustic, and even arsenic, which they introduce by first 

 making an opening, by boring with a hot iron, or otherwise, into 

 the bony swelling, and into a small hole thus made they introduce 

 some of their caustic. I was once consulted in a case of this 

 kind, in which the farrier had employed arsenic. It produced a 

 dangerous sloughing, and the horse was nearly destroyed by it. 



[It must be confessed that whatever treatment we may employ 

 for spavins, the majority of cases will be unsuccessful, — the 

 lameness will still remain. This is owing to the disease affecting 

 the deep-seated parts of the joint, and the synovial membrane 

 itself. In some cases we find, on dissection, that the small bones 

 of the hock are in a carious state, and the synovial membrane 

 and cartilage ulcerated. In other instances we find the disease 

 existing between the tibia and astragalus ; the prominence or 

 ridge on the former bone being rough and deprived of cartilage, 

 and the synovial membrane around it in a state of inflammation. 

 A similar appearance is presented by the corresponding portion of 

 the astrag-alus, thouo;h not to the same extent. A sort of notch 

 is often perceived on the ridge of the tibia, without any attend- 

 ing lameness; the joint, however, in these cases, is entirely free 



