432 



DISEASES OF THE HORSE'S FOOT 



the bone are accompanied by well-marked lesions on its 

 gliding or postero-inferior surface, and by evidences of an 

 osteoplastic periostitis along its edges. 



That an osteoplastic periostitis has been in existence is 



Fig. 



162.— A Foot with the Seat of Navicular Disease 



EXPOSED. 



On the anterior surface of the perforans fibres of the tendon are seen 

 to be torn away from their abnormal adhesion with the navicular 

 bone, while others are seen to be still attached thereto. The 

 surface of the navicular bone itself exhibits small defects in the 

 bony substance, which have been brought about by a rarefactive 

 ostitis. 



a, The perforans tendon cut through and reflected ; h, tlie sole. 



witnessed by the appearance along the edges of the bone of 

 numerous outgrowths of bone, termed osteophytes (see 

 Fig. 163). 



The interosseous and posterolateral ligaments of the 



