onsequently less
expansion of the heels is necessary than in the fore feet, where the
weight is first received on the heels. Any interference with the
expansibility of this part of the foot interferes with locomotion and
ultimately gives rise to lameness. Usually but one foot is affected at
a time, but when both are diseased the change is greater in one than in
the other. Occasionally but one heel, and that the inner one, is
contracted; in these cases there is less liable to be lameness and
permanent impairment of the animal's usefulness. According to the
opinion of some of the French veterinarians, hoofbound should be divided
into two classes--total contraction, in which the whole foot is shrunken
in size, and contraction of the heels, when the trouble extends only
from the quarters backward. (Pl. XXXV, figs. 4 and 7.)

_Causes._--Animals raised in wet or marshy districts, when taken to
towns and kept on dry floors, are liable to have contracted heels, not
alone because the horn becomes dry, but because fever of the feet and
wasting away of the soft tissues result from the change. Another common
cause of contracted heels is to be found in faulty shoeing, such as
rasping the wall, cutting away the frog, heels, and bars; high calks and
the use of nails too near the heels. Contracted heels may happen as one
of the results of other diseases of the foot; for instance, it often
accompanies thrush, sidebones, ringbones, canker, navicular disease,
corns, sprains of the flexor tendons, of the sesamoid and suspensory
ligaments, and from excessive knuckling of the fetlock joint.

_Symptoms._--In contraction of the heels the foot has lost its circular
shape, and the walls from the quarters backward approach to a straight
line. The ground surface of the foot is now smaller than the coronary
circumference; the frog is pinched between the inclosing heels, is much
shrunken, and at times is affected with thrush. The sole is more concave
than natural, the heels are higher, and the bars are long and nearly
perpendicular. The whole hoof is dry and so hard that it can scarcely be
cut; the parts toward the heels are scaly and often ridged like the
horns of a ram, while fissures, more or less deep, may be seen at the
quarters and heels following the direction of the horn fibers. (Plate
XXXVI, fig. 10.) When the disease is well advanced lameness is present,
while in the earlier stages there is only an uneasiness evinced by
frequent shifting