_The symptoms_ vary with the extent of the injury. Slight bruises or abrasions result in local swelling and soreness that disappear within a few days. Laceration of skin interferes with the movement of the knee and the animal may be quite lame. The part becomes swollen and painful. In injuries involving the sheaths of the tendons and the synovial membrane, the pain is severe and the accompanying inflammation may take on a serious form. _The preventive treatment_ should not be overlooked. Horses should be trained to carry the head at a proper height when moving. The driver should handle the reins properly and keep his attention on the horse or horses that he is driving. Superficial bruises require no special treatment other than rest. Laceration of the skin and underlying tissue requires complete rest and careful removal of any particles, of dirt and gravel that may be present in the wound. Shreds of tissue that may take no part in the healing should be cut away. The hair in the region of the wound should be trimmed short. Careful and repeated dressings with antiseptics are necessary until the inflammation has largely disappeared and healing is rapidly taking place. It may be advisable to tie the horse in the stall so that it can not lie down. DISTENDED SYNOVIAL SACS, JOINT SHEATHS AND BURSAE, "GALLS."--Soft enlargements may occur in the region of the knee and fetlock. They are commonly termed "galls," "wind-galls," or "road-puffs." They are usually due to the sheaths surrounding the tendons becoming distended with synovia. "Galls" are caused by strains, direct injury to the part and severe, continuous work. Certain individuals may develop this class of blemishes without being subject to any unusual conditions. This condition is seldom accompanied by lameness. _The treatment_ may vary in the different cases. If the distended sheath, or bursal enlargement, is caused by a direct injury or strain, cold bandages should be applied and the part given as complete rest as possible. "Wind-galls" may be removed by a surgical operation. It is not advisable to attempt the removal of "road-puffs." Rest, stimulating leg washes and bandages may temporarily remove the latter. SPRUNG KNEES (BUCK KNEES).--This condition of the knee is characterized by the partly flexed condition of the region. It is best observed by standing to one side of the horse (Fig. 33). Instead of the forearm and cannon regions appearing perpendicular or in line, they are directed forward. This condition may exist in varying degrees. Some individuals show it to a slight degree, the condition being accompanied by a weakness or shakiness of the knee when standing at rest. Sometimes, but one knee is involved.