440 IOWA DEPARTMENT OF AGRICULTURE 
disease a careful examination will reveal some increased heat in the heels 
and frog, particularly after work; as the disease progresses this becomes 
more marked, until the whole foot is hot to the touch. At the same time 
there is an increased sensibility of the foot, for the patient flinches from 
the percussion of a hammer lightly applied to the frog and heels or from 
the pressure of the smith's pincres. The frog is generally shrunken, 
often of a pale-red color, and at times is affected with thrush. If the 
heels are pared away so that all the weight is received on the frog, or if 
the same result is attained by the application of a bar shoe, the animal 
is excessively lame. The muscles of the leg and shoulder shrink away, 
and often tremble as the animal stands at rest. After months of lame- 
ness the foot is found to be shrunken in its diameter and apparently 
lengthened; the horn is dry and brittle and has lost its natural gloss 
while circular ridges, developed most toward the heels, cover the upper 
part of the hoof. When both feet are affected, the animal points first 
one hoof, then the other, and stands with the hind feet well forward be- 
neath the body, so as to relieve the fore feet as much as possible from 
bearing weight. In old cases the wasting of the muscles and the knuckl- 
ing at the fetlock become so great that the leg cannot be strightened; 
and locomotion can scarcely be performed. The disease generally makes 
a steady progress without inclining to recovery — the remission of symp- 
toms in the earlier stages should not be interpreted as evidence that the 
process has terminated. The complications usually seen are ringbones, 
sidebones, thrush, contracted heels, quarter-cracks, and fractures of the 
navicular, coronet, and pastern bones. 
SIDEBOXES. 
A sidebone consists in a transformation of the lateral cartilages found 
on the wings of the coffin bone into bony matter by the deposition of lime 
salts. The disease is a common one, especially in heavy horses used for 
draft, in cavalry horses, cow ponies, and other saddle horses, and runners 
and trotters. 
Sidebones are peculiar to the forefeet, yet they occasionally develop in 
the hind feet, where they are of little importance since they cause no 
lameness. In many instances sidebones are of slow growth and, being 
unaccompanied by acute inflammation, they cause no lameness until such 
time, as by reason of their size, they interfere with the action of the 
joint. 
Causes. — Sidebones often grow in heavy horses without any apparent 
injury, and their development has been attributed to the over-expansion 
of the cartilages caused by the great weight of the animal. Blows and 
other injuries to the cartilages may set up an inflammatory process 
which ends in the formation of these bony growths. Highheeled shoes, 
high calks, and long feet are always classed among the conditions which 
may excite the growth of sidebones. They are often seen in connection 
with contracted heels, ringbones, navicular disease, punctured wounds of 
the foot, quarter-cracks, and occasionally as a sequel to founder. 
