XI. 

 DISEASES OF JOINTS. 



The diseases of the joints are numerous and important, more 

 especially when their varied activity is taken into consideration. 

 Joints consist of bones, articular cartilage, synovial membrane, 

 capsular and binding ligaments, fat, blood vessels, and nerves. 

 They are divided into three classes — the immovable, the mova- 

 ble, and the mixed. It is only with the two latter classes 

 that we have to deal. The mixed joints are simply joined to- 

 gether by powerful binding ligaments, the end of the bones 

 being padded with fibro-cartilage. This simple kind of articu- 

 lation is subject to but one form of disease, chronic inflamma- 

 tion, causing the gradual conversion of the fibro-cartilaginous 

 pad into bony tissue. In this manner the vertebral column of 

 the dorsal region is converted into an unyielding structure, im- 

 pairing the natural movements of the horse. 



Cause. — It is caused by placing too great weight upon the 

 back, and by a constitutional diathesis. The bones degenerate, 

 becoming fragile and liable to fracture from trivial causes. 



Symptoms. — The symptoms of this disease are very obscure; 

 some slight stiffness about the loins may be observed. There 

 will be disinclination to lie down, with more or less shivering. 

 Cart horses are affected more frequently than any other class, 

 but it is sometimes seen in Jiunters and hack horses. Horses 

 suffering with this disease occasionally present symptoms of par- 

 tial paralysis; there will be an uncertain gait, crossing the hind 

 legs, and reeling. There will be great difilculty in backing, ac- 

 companied with a peculiar and sudden quivering elevation of 

 the tail. 



Treatment. — Kest the animal and give eight drachms of 

 aloes. Drachm doses of the tincture of belladonna may be given 

 12 ( 177 ) 



