324 THE HORSE. 



considered to be sufficiently restored to render it tolerably safe to 

 use the horse again in the same way which originally produced it. 



DISLOCATION. 



By Dislocation is meant the forcible removal of the end of a 

 bone from the articulating surface which it naturally occupies. 

 In the horse, from the strength of his ligaments, the accident is 

 not common ; those that do occur being chiefly in the hip joint, 

 and in that between the patella and the end of the femur. 



Dislocation of the hip joint is known by the rigidity of 

 the hind leg, which cannot be moved in any direction, and is 

 carried by the horse when he is compelled to attempt to alter his 

 position. There is a flatness of the haunch below the hip, but 

 the crest of the ilium is still there, and by this the accident 

 may be diagnosed from fracture of that part. No treatment is of 

 the slightest avail, as the part cannot be reduced, and the horse 

 is useless except for stud purposes. The accident is not very 

 common. 



Dislocation of the patella sometimes becomes habitual, 

 occurring repeatedly in the same horse, apparently from a spas- 

 modic contraction of the external vastus muscle, which draws the 

 patella outwards, and out of the trochlea formed for it in the 

 lower head of the femur. When the cramp goes off", the patella 

 drops into its place again as soon as the horse moves, and no 

 treatment is required. Occasionally, however, the dislocation is 

 more complete, and nothing but manual dexterity will replace the 

 bone in its proper situation. Great pain and uneasiness are 

 expressed, and the operator must encircle the haunch with his 

 arms and lay hold of the patella with both hands, while an assist- 

 ant drags forward the toe, and thus relaxes the muscles which are 

 inserted in it. By forcibly driving the patella into its place it 

 may be lifted over the ridge which it has passed, and a snap 

 announces the reduction. 



WOUNDS OF JOINTS. 



The knee is the joint most frequently suffering from wound, 

 being liable to be cut by a fall upon it, if the ground is rough ; 

 and if the accident takes place when the horse is going at a rapid 

 pace, the skin, ligaments, and tendons may be worn through by 

 friction against the plain surface of a smooth turnpike road. 

 Whether the joint itself is injured, or »nly the skin, the accident 

 is called a " broken knee," and for convenience sake it will be 

 well to consider both under the present head. 



When a broken knee consists merely in an abrasion of the 

 skin, the attention of the groom is solely directed to the restora- 

 tion of the hair, which will grow again as well as ever, if the 



