118 DISEASES OF THE HORSE’S FOOT 
atrophied by reason of the continual pressure exerted upon 
it by the ingrowing horn of the wall and the bars. The 
median and lateral lacune of this organ, from being fairly 
broad and open channels, become pressed into mere crack- 
like openings (see the commencing of this condition in 
Fig. 80, and a badly wasted frog in Fig. 74a). As the case 
goes on, the lateral branches of the frog entirely disappear, 
and all that is left of the organ is a remnant of its body or 
cushion, now wedged in tightly between the bars. Follow- 
ing upon the disappearance of the frog, we find that the 
bars are in contact, or, in some cases, actually overlapping 
each other at their posterior extremities. 
At this stage, perhaps, the whole condition has become 
ageravated by a foul discharge from the place originally 
occupied by the frog, and the foot, especially in the region 
of the heels, has become hot and tender—really a form of 
local and subacute laminitis. 
The long-continued inflammation, although only of a low 
type, renders the horn of the hoof hard and dry, and only 
with difficulty will the ordinary foot instruments cut it. 
This in its turn leads to cracks and fissures in various 
places, but more especially in the bars and what is left of 
the frog. Often, too, cracks will appear in the horn of the 
quarters, and a troublesome and incurable form of sand- 
crack results. 
An animal with contraction advanced as far as this, espe- 
cially if confined to one foot, goes unmistakably lame. With 
both feet affected, he ordinarily starts out from the stable ina 
manner that is commonly called ‘ groggy.’ In other words, 
the gait is uncertain, and feeling; and stumbling is frequent. 
Anyone who has had the misfortune to drive an animai 
with feet in this condition knows full well that every little 
irregularity in the road at once makes itself felt to the feet, 
and that the animal, as time goes on, learns to carefully avoid 
any suspicious-looking group of stones he may see. To drive 
an animal like this is to keep one’s self continually on 
tenter-hooks, for, sooner or later, the inevitable happens, 
and the animal comes down. 
