188 DISEASES OF THE HORSE’S FOOT 
position, there will ‘still be maintained a tread that is 
normal. To our minds harm is far more likely to arise 
from a shoe of this class through the thinned iron heels of 
the shoe becoming attenuated under wear to the point of 
bending, and so inflicting an injury upon the adjoining sole. 
Similarly, this last remark with regard to the thinning 
of the heels of the shoe will apply to a shoe with too 
broad a web. As the thinning of the shoe proceeds with 
wear, the inner portion of the thinned branch is bent up 
on to the sole, and again inflicts the injury. 
The matter of bearing is also of importance when con- 
sidering the causation of corn. In a previous chapter we 
have already described the correct bearing as that which 
includes the whole of the lower margin of the wall and the 
white line, and just impinges on the sole. Any marked 
deviation from that will, if long continued, be followed by 
injury to the foot. 
With the bearing surface of the shoe too narrow—in 
contact with the wall solely, or perhaps only a portion of 
it—it is evident that a large proportion of the foot that 
should properly bear weight is thrown out of action. A 
heavy strain is imposed on the white line, and undue 
descent of the sole and contraction of the heels brought 
about. Again the result of this is compression and bruising 
of the tissues around the seat of corn. 
With its bearing surface too wide, the shoe immediately 
exerts direct pressure upon the sole with every movement 
of the animal. The sole normally is not made to receive 
this, and harm is bound to result. 
Among other ill-fitting shoes we may mention the one 
with branches too short, and the one with the extremities 
of the branches too pointed. In the first case, as wear of 
the shoe proceeds, the thinned end is far more likely to 
turn in under the seat of corn than is a shoe with branches 
of ordinarily correct length. It is evident in the second 
case that the pointed branch, when thinned, is a more 
dangerous agent than the branch which is nearer the 
square at its end. 
