438 IOWA DEPARTMENT OF AGRICULTURE 
snakes, a painful swelling occurs about the bitten part, which is fol- 
lowed by labored breathing, weakness, retching, fever, and death from 
collapse. The animal usually recovers if it can be kept alive over the 
third day. In treating the animal, a tight ligature should be passed about 
the part above the wound to keep the poison from entering the general 
circulation. Wash out the wound thoroughly with antiseptics and then 
appxy a caustic, such as siiver nitrate, or burn with a hot instrument. 
A subcutaneous injection of one-fourth dram of 1 per cent solution of 
chromic acid above the wound is also beneficial. Cold water may be ap- 
plied to the wound to combat the inflammation. Bites of rabid dogs 
produce an infected wound, and the virus of rabies introduced in this 
manner should be removed or destroyed in the wound. Therefore produce 
considerable bleeding by incising the wound, w^ash out thoroughly with 
10 per cent solution of zinc chloriae and then apply caustics or the 
actual cautery. 
NAVICULAR DISEASE. 
Navicular disease is an inflammation of the sesamoid sheath, induced 
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 sesamoid sheath becomes 
involved subsequently by an extension of the inflammatory process. 
The thoroughbred horse is more commonly affected than any other, 
yet no class or breed of horses is entirely exempt. The mule, however, 
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 affectd. 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 now navicuar disease may be caused 
by conditions and usages common to nearly all animals, it is necessary 
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 the 
greater is the shock which the fore feet must receive as the body is 
thrown forward by the propelling force of the hind legs. This shock 
could not be withstood by the tissues of the fore feet and legs were it not 
that it is largely dissipated by the elastic muscles w^hich bind the shoul- 
der to the body, the ease with which the arm closes on the shoulder 
blade, and the spring of the fetlock joint. But even these means are not 
sufRcient within themselves to protect the foot from injury; so nature 
has further supplemented them by placing the cofSn joint on the hind part 
of the coffin bone instead of directly on top of it, whereby a large part of 
the shock of locomotion is dispersed before it can reach the vertical 
column represented by the cannon, knee, and arm bones. A still further 
provision is made by placing a soft, elastic pad— the frog and plantar 
cushion — at the heels to receive the sesamoid expansion of the flexor 
tendon as it forced dovv-nward by the pressure of the coronet bone against 
