DOMESTIC ANIMALS. 83 



from the bottom. Hot fomentations and poultices are 

 beneficial. The horse should be kept in slings. 



DISLOCATIONS. 



THE displacement of bones from their normal position 

 in a joint is comparatively a rare condition in the horse 

 and ox. But in dogs it is a frequent accident. Although 

 it is possible to have dislocations of many of the joints 

 in horses, there is only one that is common enough to 

 require notice in this short work. 



DISLOCATION OF THE PATELLA, OR D1S- 

 PLACEMENF OF ONE OF THE BONES OF THE 

 STIFLE. This bone is seen at x in the figure of the 

 skeleton on page 1, and is the analogue of the knee-pan 

 in man. This is very frequently the seat of dislocation, 

 the patella becoming displaced by slipping out over the 

 prominence on the femur. 



Causes. The patella is kept in position by three 

 ligaments holding it down, one on each side and the 

 other in the middle. The eminence on the femur also 

 assists to keep it in its proper place. Above, it is held 

 in place by some of the muscles on the front of the 

 thigh. Now, I am of the opinion that the under liga- 

 ments sometimes become unduly stretched, so that they 

 fail to hold the bone down far enough. It may be said 

 that they become too long, and the contractions of the 

 muscles above will pull the bone from its normal posi- 

 tion. At any rate we know that some horses while even 

 standing in the stall, if made to move, will displace the 

 patella, and when made to change position again, the 



