190 DISEASES OF THE HORSE’S FOOT 
stone. The stone becomes firmly wedged in between the 
inner border of the branch of the shoe and the bar or the 
frog. With every step the animal takes it becomes wedged 
more tightly into position. Projecting below the level of 
the lower surface of the shoe, it imparts the concussion 
it thus obtains directly to the sole. A bruise—and a bad 
bruise—is the result. 
Finally, it cannot be denied that the work the horse is 
put to is largely responsible for the causation of corn. In 
country animals corns are comparatively rare, while in 
animals in town, almost constantly upon hard paving, they 
are common. This seems to point strongly to the fact that 
concussion through constant work upon unyielding roads is 
a great factor in their production. 
Symptoms. — Unless the discoloration of the horn is 
accidentally discovered by the smith, the simple, dry corn 
may go undetected. The disturbance excited by it is so 
small, and the pain occasioned so slight, that the patient 
may offer no indication of its existence. 
Ordinarily, however, the first symptom is that of pain. 
The animal goes feelingly with one or both feet, in some 
cases even showing decided lameness. The lameness, how- 
ever, is in no way diagnostic, and the lesion itself must be 
discovered before an exact opinion can be pronounced. 
As an aside, it is well to observe in this connection that 
a negative opinion as to the existence of corn should never 
be given unless the superficial layers of horn have first 
been removed with the knife. 
When standing at rest the animal exhibits signs more or 
less common to all foot lamenesses. He ‘ points’ the foot— 
in other words, the limb is slightly advanced, the fetlock 
partly flexed, and the heels from off the ground. When 
both feet are affected they are pointed alternately, and the 
animal often manifests his uneasiness by repeated pawing 
movements, and by scraping his bedding behind him. 
Should the injury run on to suppuration, the lameness 
becomes most acute. The pawing movements become more 
pronounced, and there is evident disinclination on the part 
