DISEASES OF THE FOOT 169 



The margins of a quarter-crack and the wall just posterior 

 and below it should be cut away until (iuite thin. The bearing 

 margin should then be trimmed so that it does not rest on the 

 shoe. A bar shoe that does not press on the frog may be used. 

 Light blisters to the region of the coronet help in stimulating 

 the growth of the horn. Rest is advisable. 



Corns. — This term is applied to injuries to the foot caused 

 by bruises or continuous pressure to the posterior portion of the 

 sole. This condition is common in the forefeet. 



The predisposing causes are faulty conformation that favors 

 pressure from the shoe on the sole between the bars and wall and 

 weak heels. Corns are commonly met with in feet having con- 

 tracted quarters. The principal exienml causes are wrong 

 methods of shoeing and allowing the shoes to remain on the feet 

 for too long a period. 



A common sympdom of corns is lameness. In order to relieve 

 the pressure over the inflamed part, the animal stands with the 

 foot slightly flexed at the fetlock. The lameness is not charac- 

 teristic. It is only by a local examination of the foot, made 

 by pressing on the sole or cutting away the horn, that we are 

 able to form a positive diagnosis. 



We describe the diseased changes by using the terms dry, 

 moist and suppurative corns. In the dry corn we find the horn 

 stained and infiltrated with blood. In the moist corn the hoof 

 may be colored the same as in the former, but in addition there 

 is a space between the vascular and horny tissue that is filled 

 with a serous-like fluid. If this collection of fluid becomes in- 

 fected with pus organisms and is changed to pus. it is then 

 termed a suppurative corn. Sometimes the pus pushes its way 

 upward and backward between the sensitive lamina; and the 

 wall, and makes its appearance at the margin of the coronary 

 band in the region of the quarters or heels. This usually occurs 

 when the tissues beneath the horny frog become bruised or the 

 sensitive tissue pricked by a nail. It is commonly termed 



