138 HORSESHOEING. 



3. Calk Wounds of the Coronet. 



All tread-wounds of the coronet, caused by the calks of the 

 opposite shoe, or by the shoes of other horses, are known as calk 

 wounds, or simply as " calking." The injury itself is either a 

 bruise or a bruised wound, followed by inflammation of the 

 coronary cushion and an interruption in the formation of horn 

 at that point. It occurs most often in winter from sharp calks, 

 especially on the hind feet. The common seat of the injury is 

 the coronet of the toe and the inner side of the foot. 



The inflammation terminates either in resolution — that is, 

 passes gradually away, leaving the tissues apparently normal — or 

 in suppuration. The perioplic horn-band, which is usually loos- 

 ened from the perioplic band by the injury, does not again unite. 

 For this reason, and because of the interruption in the formation 

 of horn at the seat of injury, there results a transverse depres- 

 sion or cleft in the wall. 



The shoeing has to deal only with the lameness that may be 

 present as a result of the calking. The section of the wall con- 

 taining the lesion should be shortened, so that it will not press 

 upon the shoe. Serious calk wounds, as a rule, require treat- 

 ment by a veterinarian. 



4. Corns (Bruised Sole). 



The expression " corns" is apphed to nearly all bruises of the 

 pododerm of the posterior half of the foot, with the exception of 

 the frog, which are apparent to the eye as yellowish, reddish, or 

 bluish-red discolorations of the horn of the sole and white line. 



The surface of the pododerm (fleshy leaves and villi) is chiefly 

 involved, and almost without exception there is rupture of small 

 blood-vessels and an outpouring of blood between the pododerm 

 and the horn. The blood penetrates the horn-tubes and causes 

 the above-mentioned staining. By subsequent growth of horn 

 these stained patches are carried downward, and are finally 

 uncovered and brought to sight in paring the hoof. 



The seat of corns is either on the fleshy leaves of the quarters, 



