406 DISEASES OF THE HORSE’S FOOT 
tissues immediately surrounding them were inflamed. 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 corone. 
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.’* 
9, FRacTURES oF THE Os PEDISs. 
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. 
Reported Cases.—Two interesting cases of fractured os 
pedis are reported by Mr. Gladstone Mayall, M.R.C.V.5., 
in the Veterinary Record, vol. xiv., p. 54: 
* R. Crawford, M.R.C.V.S., Veterinary Record, vol. viii., p. 478. 
