208 DISEASES OF HORSES AND CATTLE. 



CHAPTER XIX. 



DISEASES OP THE JOINTS. 



There are three classes of joints: Immovable, 

 movable, and mixed. The immovable joints are 

 those which connect flat bones i together, such as 

 the bones of the face and head, and are not subject 

 to any special disease. It is the movable and the 

 mixed which we have to deal with, especially those 

 of extensive motion. These joints are connected 

 by binding and capsular ligaments, and the ends 

 of the bones are incrusted with cartilage and the 

 true joints lubricated with synovia, secreted by the 

 synovial membrane which lines the capsular liga- 

 ment. The true joints are very liable to injuries, 

 and from the nature of their structure very liable 

 to severe inflammation, ulceration, and ossifica- 

 tion. It is very common in cities to find old horses 

 which have been subjected to heavy work with sev- 

 eral of the lumbar vertebrae ossified. This is 

 caused by the weight on their backs and from slip- 

 ping. The cartilages connecting the bones are 

 first irritated, then formed into bone, ending in a 

 solidification. The knee is not liable to strains, 

 but is often injured by falls and kicks and other 

 injuries. The term "broken knees" is used when 

 an animal falls and breaks the skin or otherwise 

 injures the knee joint. When it is severe the ani- 

 mal suffers great pain and is very lame. 



