FAULTY CONFORMATION 147 
When following the subacute form of laminitis, the 
changes characterizing pumiced-foot are slow in making 
their appearance. The animal at first goes short, and the 
lameness thus indicated gradually becomes more severe, 
until the animal is no longer able to work. The feet 
become hot and dry, the hoof loses its circular form, and 
the growth of -horn at the heels becomes excessive. At 
this stage the appearance of bulging at the sole begins to 
make itself seen. Later, the outer surface of the wall 
becomes ‘ringed’ or ‘ribbed,’ the rings being somewhat 
closely approximated in the region of the toe, and the 
Fic. 81.—Hoor with tHe Riss or RINGS CAUSED BY CHRONIC 
LaMINITIS. 
distance between them gradually widening towards the heels. 
The wall too, especially in the region of the toe, instead of 
running in a straight line from the coronary margin to the 
shoe, becomes concave. It is this change, together with 
the appearance of the rings, that indicates the loosening 
of the attachment of the os pedis to the wall, and its after- 
wards backward and downward direction (see Fig. 124). 
As a sequel of acute laminitis, these changes make their 
appearance with more or less suddenness, and are generally 
complicated in that they owe their occurrence to the forma. 
tion of pus within the horny box. 
Treatment.—Pumiced-foot is always a serious condition. 
The animal is useless for work upon hard roads or town 
10—2 
