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 

 articulation 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 



