270 



DISEASES OF THE HORSE'S FOOT 



any rate of the outer layer of the periosteum, is in laminitis 

 constant even, we repeat, in a mild case. 



When the case is a serious one we have ample evidence 



Fig. 118. — Showing Changes in the Os Pedis with Laminitis of Long 

 Standing, (a, Viewed from the front ; h, viewed from the side.) 



The porous condition of the bone, which is here shown, is a result of a rare- 

 fying or rarefactive ostitis. This specimen also illustrated (what the 

 photograph cannot show) an accompanying condition of condensation of 

 hone, or osteoplastic ostitis. (For a fuller description of the changes 

 occurring in these forms of ostitis, see Chapter XL) 



to show that ostitis exists, and exists in a severe form. 

 The bones become vastly altered in shape, a process of 

 absorption leads to the formation of large, irregular cavities 

 within their substance, and what of the bone is left is 



