THE POINTS OF THE HORSE 



153 



are due to strains, and while an unsoundness, are not of 

 the more serious kind. 



Bog spavin is a small, round form of tumor, located 

 in the front and inner side of the hock. If pressed, it may 

 appear on the outside and rear part of the hock. 



Thoroughpin is a swelling in the rear part of the hock 

 at its thinnest point. Here, 

 under ordinary conditions, the 

 hock is curved to form grace- 

 ful outlines with a pronounced 

 depression. If thoroughpin 

 occurs, a swelling will be no- 

 ticeable on each side of the 

 hock at this point. Bog spav- 

 ins, thoroughpins, or a puffed 

 condition about the hocks, are 

 seen most frequently on large, 

 heavy horses that have what 

 are called thick, meaty hocks. 

 Horse dealers are inclined to 

 refer to these as little puffs 

 that will disappear with work, 

 and so minimize their import- 

 ance. It is true that heavy 

 horses that stand in the stable, 

 frequently swell in the lower 

 half of the legs, a condition that exercise removes, but bogs 

 and thoroughpins are distinct unsoundnesses that exercise 

 will not drive away, and that injure the sale value of the 

 horse. 



Sidebone is found in the rear part of the front foot on 

 the coffin bone at the crown or top of the hoof. It is due 

 to the hardening of cartilages, whereby they take on a bony 



Fig. 82. The hock from one side, 

 showing bog spavin in front and curb 

 behind. Reproduced from " The Dis- 

 eases of the Horse," U. S. Dept. of 

 Agriculture. 



