124 DISEASES OF THE HORSE’S FOOT 
Excessive paring of the bars, to which we have already 
partly alluded, is also an active agent in bringing about an 
inward growth of the horn of the heels and quarters. The 
bar, or inflexion of the wall at the heel, by means of its 
close contact with the frog, communicates the outward 
movements of that organ to the wall of the hoof. With the 
bar removed, the outward movements of the frog under pres- 
sure are naturally rendered of no account, and a proper and 
intermittent expansion of the wall denied it. The same evil 
follows, though to a less extent, excessive pari le. 
The Shape of the bearing surface of the shoe is often to 
be blamed. Where this is concave—‘ seated ’—and the 
‘seating’ is carried back to the heels, it is easy to see ‘that, 
when weight is on the foot, there is an ever-present_ten- 
dency for the bearing edge of the wall to slide down 
towards the inner edge of the shoe. This tendency, 
operating on both the inner and outer wall simultaneously, 
must strongly favour contraction. 
A further wrong practice is that of continuing the _nail- 
ing too far towards the heels. In our opinion this is not 
now often met with. When it occurs its effect is, of course, 
to prevent those movements of expansion of the wall which 
we now know to be normal and most marked at the heels. 
It may be remarked of the build of the shoe, or of errors 
in the preparation of the foot, that neither are of much 
moment. Neither are they. But when one stays to con- 
sider that errors of this description are practised not only 
once, but each time the horse goes to the forge, and that 
with some of them—those relating to the build of the shoe 
—the injury thereby brought about’ is inflicted not only 
once, but every day that particular shoe is worn, then it is 
not to be wondered at that, sooner or later, ill consequences 
more or less grave result. 
Prognosis.—This will depend to a very large extent upon 
the conformation of the limb, and upon the previous dura- 
tion of the contraction. Contraction of long standing, 
where atrophy of the sub-lying, soft structures and the 
pedal bone may be expected, will prove obstinate to treat- 
