406 DISEASES OF THE HORSE'S FOOT 



tissues immediately surrounding them were intlamed. On 

 the centre of the articular surface of the coronary bone 

 a thin red ring was noticed, and the portion of cartilage 

 within it seemed raised. With the point of a scalpel this 

 portion was lifted, and was found to be not only cartilage, 

 but a layer of bone completely detached from the os coronne. 

 On removing the bones from the hoof the rest of the bone 

 was quite normal, as was the pedal bone. 



' Fig. 158 shows the articular surface of the coronet with 

 the fracture in situ ; and Fig. 159 the surface from which 

 the broken portion is removed and laid to the side of the foot. 



' Some interesting questions arise. How was the fracture 

 caused ? When did it occur ? Between the broken portion 

 and the main bone there was a layer of granulation tissue, 

 so that it is certain the injury existed before the blister was 

 applied, and it may possibly have existed from the com- 

 mencement of the lameness.'* 



2. Fractukes of the Os Pedis. 



These also are a result of the causes we have before given. 

 The OS pedis is also liable to fractures from pricks, from 

 treads in the region of the wings, and from the malnutrition 

 and careless use of the foot sometimes following neurectomy. 



It is interesting to note that, with fracture of this bone, 

 lameness is nearly always excessive, but that at times it 

 may be entirely absent. Crepitus is, of course, denied us, 

 and in nearly every instance the case is only diagnosed 

 when the lameness persists and pus commences to form, or 

 when grave changes in the normal shape of the foot compel 

 our attention to the parts. When it is the continued forma- 

 tion of pus that draws our notice to something more than 

 ordinarily grave, it is in giving exit to the pus that the 

 fracture is nearly always discovered. 



Rejjorted Cases. — Two interesting cases of fractured os 

 pedis are reported by Mr. Gladstone Mayall, M.E.C.V.S., 

 in the J^cteriiiav)/ Record, vol. xiv., p. 54 : 



* K. Crawford, M.R.C.A^S., Veterinary liccord, vol. viii., p. 478. 



