DISEASES OF THE FETLOCK, ANKLE, AND FOOT, 435 



oakum balls, and a roller bandage. After a few days the wound will 

 be covered with a new, white horn, and only the oakum and bandages 

 will be needed. As the new quarter grows out, the lameness dis- 

 appears, and the patient may be shod with a bar shoe and returned to 

 work. 



In all cases of sand crack the growth of horn should be stimulated 

 by cauterizing the coronary band or by the use of blisters. In simple 

 quarter crack recovery will often take place if the coronet is blistered, 

 the foot shod with a " tip," and the patient turned to pasture. 



The shoe in toe crack should have a clip on each side of the fissure 

 and should be thicker at the toe than at the heels. The foot should be 

 lowered at the heels by paring, and spared at the toe, except directly 

 under the fissure, where it is to be pared away until it sets free from 

 the shoe. 



When any of the complications referred to above arise, special 

 measures must be resorted to. For the proper treatment of gangrene 

 of the lateral cartilage and extensor tendon and caries of the cofiSn 

 bone reference may be had to the articles on quittors. If the horny 

 tumor, known as keraphyllocele, should develop, it is to be removed 

 by the use of the knife. Since this tumor develops on the inside of 

 the horny box and may involve other important organs of the foot in 

 disease, its removal should only be undertaken by a skillful surgeon. 



NAVICULAR DISEASE. 



Navicular disease is an inflammation of the sesamoid sheath, in- 

 duced by repeated bruising or laceration, and complicated in many 

 cases by inflammation and caries of the navicular bone. In some 

 instances the disease undoubtedly begins in the bone, and the ses- 

 amoid sheath becomes involved subsequently by an extension of the 

 inflammatory process. (Plate XXXIV, fig. 5.) 



The Thoroughbred horse is more commonly affected than any other, 

 yet no class or breed of horses is entirely exempt. The mule, how- 

 ever, seems rarely, if ever, to suffer from it. For reasons which will 

 appear when considering the causes of the disease, the hind feet are 

 not liable to be affected. Usually but one fore foot suffers from the 

 disease, but if both should be attacked the trouble has become chronic 

 in the first before the second shows signs of the disease. 



Causes. — ^To comprehend fully how navicular disease may be caused 

 by conditions and usages common to nearly all animals, it is neces- 

 sary to recall the peculiar anatomy of the parts involved in the process 

 and the functions which they perform in locomotion. 



It must be remembered that the fore legs largely support the weight 

 of the body when the animal is at rest, and that the faster he moves 



