162 



NON-SPECIFIC OR GENERAL DISEASES 



over the navicular bone before it becomes attached to the inferior 

 face of the pedal or digital bone. 



Side-bones, — This is a chronic inflammation of the lateral 

 cartilages of the foot that results in their ossification (Fig. 38). 

 This unsoundness is common in heavy horses, especially if 

 worked on city streets. The inflammation affects the cartilages 

 of the front feet, rarely those of the hindfeet. 



The hereditary tendency toward the development of side- 

 bones is an important predisposing factor. It is not uncommon 



Pig. 38. — A very large side bone. 



to meet with this unsoundness in young horses that have never 

 been worked. Low, weak heels, flat, spreading feet, or any 

 other faulty conformation of the foot are predisposing factors. 



The character of the work is an important exciting cause. 

 Continuous work over paved streets, especially if the horse is 

 shod with high-hooled shoes, increases the shock received by the 

 elastic apparatus of the foot. This produces more or less irri- 

 tation to the lateral cartilages, which may result in their com- 

 plete ossification. Punctured wounds in the regions of the carti- 

 lage may cause it to become inflamed and changed to bone. 



The following symptoms may be noted. Farm horses that 



