342 DEFORMITIES AND DISEASES OF THE HOOF. 



with the exception of pronounced upright hoofs, all show 

 moderate convergence of the posterior parts of the heel 

 walls. 



Horses with contracted heels usually stand with the fetlock 

 upright while the axis of the foot is not infrequently hent 

 backwards (see fig. 201). The diseased foot is placed a little 

 in advance and is also slightly flexed. When both feet are 

 diseased the animal rests them alternately, and when the con- 

 dition has existed for long there is bending at the knees. 

 Both the last named symptoms result from tenderness of the 

 sensitive structures. 



Tlie gait is low, ' shuttling,' and uncertain, especially for 

 the first few steps. The foot strikes against obstacles and the 

 animal stumbles, even on fairly level ground. This symptom, 

 most marked when the horse is ridden, renders him both 

 unpleasant and unsafe. At a trot he fails to extend the front 

 limbs, and if only one hoof is affected may go quite lame. If 

 the shoes impede expansion of the heels, the pain may even 

 become acute enough to throw the horse off its feed, and cause 

 it to lie continually. The pain forces the animal to go on 

 the toe, and there is at first increased wear of that part of the 

 shoe, though, when the process is complete, the shoe may again 

 be worn level. Manual examination reveals slightly increased 

 warmth at the heels, pulsation of the digital arteries, pain on 

 pressing and on tapping the heels. 



In consequence of the changes going on in the hoof it loses 

 its normal form and becomes longer and narrower, the horny 

 sole being usually more concave, and the horn of the heels 

 weaker and less tough. The bulbs are atrophied so that the 

 frog partly disappears. On dissection, there is often to be 

 found in the posterior half of the foot atrophy of the coronary 

 band, of the plantar cushion, and sometimes even of the os 

 pedis. Atrophy of the pedal bone is best seen at the wings, 

 but in severe cases may extend even to other parts. 



As the hoof contracts at the heels the sensitive sole is sub- 

 ject to continued pressure in direct proportion to the degree to 

 which the heels converge and to which they are thrust down- 

 wards. Both conditions are most marked in flat feet, and, as a 

 consequence, flat feet with contracted heels almost always exhibit 

 corns as a complication. The point which suffers most is perhaps 



