The claws of the cat are, as we have seen, protected, when not required for use, by being drawn back into the sockets, which are peculiar to this class of animals. This protection keeps the points of the claws perfectly sharp for catching their prey; for if they protruded as they do in the dog, they would become worn off and be as dull as those of the latter. The claws sometimes get injured by being broken when seizing rough objects, or from accidents, which renders them excessively sore. If the nail only has been loosened, it should be trimmed off carefully, and a little balsam applied to the uncovered bone, which will soon grow a new claw. If, however, the bone has been injured, and has become necrosed, it should be removed. In injuries of this sort, when the bone is affected, the sooner it is attended to the better. If only the extremity of the bone is diseased, it can be scraped off, and will heal rapidly; whereas if the necrosis has extended to the joint, and has implicated the elastic ligament, healing is difficult, and amputation may have to be performed as high as the second joint.