DISEASES OF THE FEET. 249 



SIDEBONES. 



Synonym. — Ossified cartilages. 



Definition. — This disease, otherwise known as Sidehones, consists in 

 ossification of the elastic lateral cartilages or wings of the bone of the 

 foot, Fig. 129. Nature has substituted cartilage for bone in this part in 

 order to give greater elasticity towards the heels. Any alteration in this 

 structure, such as its conversion into bone, must interfere with the elas- 

 ticity of the tread, though it may not occasion positive lameness. The 



Fig. 129. 

 Ossification of the Lateral CartUages— Sidebonea. 



bony deposit may, however, be so extensive as to materially alter the shape 

 of the coffin bone; and in such cases lameness will be the inevitable 

 result. 



Heavy coarse cart horses are most subject to this disease, and in them 

 the deposit is often very large. In light horses it seldom becomes so large 

 as to be visible to the eye. The change in structure, however, is easily 

 ascertained by feeling the wings of the bone of the foot. If they are 

 affected with ossification, they will be hard and immovable instead of 

 elastic. 



Etiology. — Sidebones are generally supposed to be the result of 

 inflammation set up in the lateral cartilages by excessive concussion or by 

 an accidental blow, wound, or tread. The tendency of cartilaginous 

 structures under the influence of inflammation to become absorbed and 

 replaced by bone has been already noticed. 



It is probable, however, that they also frequently arise from the practice 



