138 



PAJITICUXAR FRACTURES. 



when it. has been nearly ■worn through by the caries of chronio 

 navicular disease. Very often this fracture is accompanied by 

 rupture of the diseased portion of the tendo perforans, and in 

 such a case the toe is immediately turned up, making the diag- 

 nosis certain ; when this complication is not present, it is more 

 difficult to arrive at a svire conclusion, and the history of the 

 ca£9 must be taken into account. The horse has been lame, but 

 eerviceable, for a long time, and all at once he becomes help- 

 lessly lame and unfit for further use. The practitioner must 

 dravr his own conclusions, and reason upon the case, as no set 

 rule can be laid down 



This form of fracture occurs very often after the operation of 

 neurotomy, from the increased freedom of motion which result* 

 upon the removal of pain ; both tendon and bone giving way,- 

 the fetlock coming to the ground, &c. I have seen one case that- 

 poDs to prove that mere fracture of the bone after this operatioi> 

 does not always cause inconvenience to the animal ; and sub-^ 

 joined are two woodcuts, of the ^lavicular bone from a hors^ 



Fias. 15 and 16 show both surfaces of the Navicular bone, 

 described in the text. 



tmnerved by me at the Veterinary College more than three years] 

 before he was destroyed. During the whole of that time hej 

 performed his work well and soundly, and ultimat-ely had to be 

 put away, owing to the occurrence of necrosis of the oa pedis. 



