DISEASES OF THE BONES 



391 



fession, who were by no means unanimous as to the cause 

 of lameness. The favourite theory was that it was a 

 sequence of " split pastern."' A post-mortem examination 

 showed that there was no fracture. There was no adher- 

 ence of the tendon to the navicular bone nor any ulcera- 

 tion. The morbid changes consisted entirely of osseous 

 deposit as shown in the photographs. The under surface 

 of the navicular bone was much enlarged and roughened 



Fig. 151. — Effects of Periostitis on the Pedal and Navicular 



Bones. 



by this bony deposit, which extended on to the os pedis, 

 causing complete anchylosis at each extremity of the 

 navicular. The lateral cartilages were healthy. The in- 

 teresting points in connection with the case are the 

 insidious commencement of osseous disease, its extensive 

 development, and the entire absence of any external mani- 

 festation, through its being confined entirely within the 

 limits of the hoof. 



