NAVICULAR DISEASE. 
25 
serious injury which compels the suspension of his limbs 
for months (it may be free from much pain), it diminishes in 
size, every part being involved in the general atrophy or wast¬ 
ing ; the hoof contracting as the enclosed tissues waste from 
what Prof. Williams calls “ diminished functional activity 
and adaptability.” The animal recovers without scar, pain, 
or lameness ; the tissues protected by the elastic skin soon 
regain their volume, but the soft tissues protected by the 
contracted hoof cannot. The hoof, having shrunk, has ac¬ 
quired a shape and size determined mostly by the coffin 
bone within. When standing idle, there is nothing to cause 
irritation, but as soon as put to work disturbances follow ; 
then, instead of a general atrophy, we find atrophies and 
changes of particular parts, according to the shape, size and 
quality of the hoof, the degree of disturbance, and the de¬ 
mand made on it. Changes , the result of “ diminished func¬ 
tional activity” and “adaptability,” and changes, the result of 
disturbance, especially at the extremities, are therefore quite 
different conditions. 
The hoof peculiar to navicular disease may be a hind one 
or a fore one ; usually small ; it has modifications. Conse¬ 
quently we find different degrees of the disease. One or 
both heels are shortened ; one or both heel cartilages are 
bent inwards ; one or both bars crowd ; one or both halves 
of the frog diminish ; one or both sides of the wall shrink, 
and the hoof is twisted, dry and hard, toeing out or in. When 
long idle, it is often cold, but when exercised it is hot. Every 
feature of the case proclaims mechanical interference by the 
“ horny box,” and demands treatment with the drawing 
knife, buttress and rasp, followed by persistent softening with 
poultices or otherwise, which will encourage repair and 
growth without the aid of the tortures now so universally 
popular in such cases. 
Where we find such disturbance at the extremity there 
must be strain of the tendon, for there is always shortening of 
it when there is atrophy, just as we find relaxation in paral¬ 
ysis when the injury is central. 
This is illustrated in cases of shortening of the flexor ten- 
