28 BULLETIN 48*7, U. s. DEPARTMENT OF AGRICULTURE. 



veloped by the cartilage changing to solid hone. They may cause 



lameness and pain, especially when the horse is driven on hard pave- 

 ment. A fistulous abscess, known as quittor, may also occur upon the 

 coronet. 



Feet. — Founder is indicated by rings and ridges around the hoof 

 wall, an abnormal projection of the toe, and a convex sole. (The 

 rings and 'ridges are close together at the toe and diverge toward the 

 heel.) Founder also causes lameness. Weak feet are subject to 

 cracking. A crack in front of the foot is known as a sand, crack, and 

 those on the quarters are known as quarter cracks. Upon the soles 

 of the feet there may be corns, or a diseased condition of the frog 

 known as thrush. 



Hocks. — It is very essential that the student knows the structural 

 outline of a perfect hock, otherwise it will be difficult to detect cer- 

 tain unsoundness common to this region. Thoroughpin is one of the 

 troubles often difficult to detect. It consists of a soft swelling having 

 its origin between the tendon and the bone, appearing just above the 

 hock. 



There may be associated with thoroughpin a trouble known as bog 

 spavin. This trouble is found in the depression that occurs on the 

 inner forward part of the hock. It is caused by the oil from the 

 joint accumulating and forming a soft swelling. Sometimes the term 

 blood spavin is applied to these swellings and to an enlargement of 

 the vein that passes the hock from the front. None of these troubles 

 are considered unsoundness in a technical sense unless the} 7 are pro- 

 ductive of lameness. Just under the hock at the rear the lijraments 

 may thicken, forming a bulging calloused enlargement known as a 

 curb. 



The worst trouble of the hocks and the most common is bone 

 spavin. Nature in her attempt to strengthen a weak hock often 

 causes a deposit of bone about the joint. Needless to state that this 

 interferes with action, causing lameness. The lameness usually 

 lessens with exercise. 



Stifle. — Be sure there are no swellings about the stifle. 



General unsoundness. — It is necessary to drive a horse hard for 

 some distance to determine if his wind is sound. By stopping him 

 quickly and listening in a position close to the neck it may be de- 

 termined whether the breathing is natural. There may be a roaring 

 or whistling sound indicating disorders of the air passages. Irregu- 

 lar, spasmodic breathing indicates heaves, another unsoundness of 

 the horse. 



Vices. — Such vices as kicking, balking, shying, and a tendency to 

 run away are not met with in draft horses to the extent that they 

 occur in lighter horses. Stable vices such as cribbing, weaving, tail 

 rubbing, and halter pulling, as well as the vices mentioned above, 



