440 DISEASES OF THE HORSE’S FOOT 
able when the animal is put to work on a rough or on a 
hard ground. Even now, however, heat of the foot or 
tenderness is so slight as to be out of all proportion to the 
alteration in gait. 
With the case thus far advanced, evidence of pain may 
be obtained by pressing with the thumb in the hollow of the 
heel. Evidence of pain may also be obtained by using the 
farrier’s pincers on the frog. These methods, however, are 
never wholly satisfactory, as a horse with the soundest of 
feet will sometimes flinch under these manipulations. 
Extreme and forcible flexion of the corono-pedal articula- 
tion also sometimes gives evidence of tenderness. In this 
case the foot is held up, the animal’s metacarpus resting 
on the operator’s knee, and the toe of the hoof pushed 
downwards with some degree of force. 
The same movement of the joint is given by causing the 
animal to put full weight upon the diseased limb, a small 
wedge of wood being first placed under the toe. In this 
manner the pressure of the perforans tendon upon the 
bursa is greatly increased, and the animal is caused to 
show symptoms of distress. 
The lameness may also be increased, and diagnosis 
helped, by paring the heels, so as to leave the frog promi- 
nent and take the whole of the body-weight. The same 
end is also obtained by applying a bar shoe. This was 
originally pointed out by Brauell, and is quoted by Zundel 
and by Moller. 
The changes in the form of the hoof may now be noticed. 
These are largely dependent on the fact that more or less 
constantly the patient saves the heel. The horn of the 
walls in this region, and the horn of the frog, is thereby 
put out of action and induced to atrophy. The hoof 
gradually assumes a more upright shape, and the heels 
contract. We thus get a hoof which is visibly narrowed 
from side to side, with a frog that is atrophied and often 
thrushy, and with a sole that is abnormally concave, hard, 
and affected with corns. 
When occurring in the hind-feet—a condition that is 
