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 coffin 
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 
