55 



when they stir or walk about, the patella, or cap, slips partly off the 

 joint, towards the outside, making a knocking noise. Very hilly 

 pastures are thought to favour the development ot the trouble in young 

 horses. The treatment consists of repeated blistering, which sometimes 

 does good, and putting on of a special shoe, thin at the heels but with 

 a thick projecting toe. But so unsatisfactory, as a rule, are the 

 various forms of treatment, that the best plan is to destroy the animal, 

 as it scarcely pays to bring it up for work, and it is of no good to breed 

 from. 



i66. Dislocation of the Patella. — Horses and cows sometimes 

 throw off the cap by jumping up too suddenly. When dislocation 

 takes place, the cap comes to the outside, on account of the ridge on 

 the femur being less on the outside than on the inside. The leg is 

 extended behind in a rigid condition, the front of the point of the toe 

 resting on the ground with the sole of the foot looking upwards and 

 backwards (see Plate X.). If in the stall the animal must be got into 

 the yard, a neck collar put on, and a strong rope passed through the 

 bottom of the collar, between the fore legs, and tied round the 

 pastern joint of the dislocated limb. The foot must then be pulled 

 forcibly forward under the belly, until the sole can rest flat on the 

 ground ; the cap must now be manipulated to the front, and held there, 

 when, on the horse stepping forward, it readily drops into its place. 

 A good blister should be applied, and the animal tied up short for a 

 week or so, to prevent it lying down, as when once the cap has been 

 disturbed, and ligaments stretched, it is apt to again become displaced. 



167. Hip Joint Dislocation. — From some extensive injury, this 

 joint occasionally becomes dislocated, being usually accompanied 

 by a fracture. The leg seems much shorter than its fellow, and does 

 not reach the ground. When the dislocation is forward, in front of 

 the articulation, the back of the leg hangs, pressing against the front 

 of the shank bone of the opposite leg, and when the dislocation is 

 backward, the front of the leg presses against the back of the shank 

 of its fellow. When the muscles are so extensively lacerated, and 

 the swelling is great, the animal is usually destroyed. 



