imal rubbing
the part the irritation is persistently increased. The hotter the
climate the more troublesome the disease.[4]

_Treatment_ consists, first, in placing the animal in a cool place and
showering the surface with cold water. The parasite may be destroyed by
rubbing the surface of the wound with iodoform and covering it with a
layer of collodion, and repeating the applications very 24 hours for 15
days, or until the sores heal up. Ether or chloroform, poured on cotton
wool and applied to the sore for two minutes before painting it with
collodion, may be used in place of iodoform.[5]

CRACKED HEELS (SCRATCHES, OR CHAPS ON KNEE AND HOCK).

This usually sets in with swelling, heat, and tenderness of the hollow
of the heel, with erections of the hairs and redness (in white skins),
with stiffness and lameness, which may be extreme in irritable horses.
Soon slight cracks appear transversely, and may gain in depth and width,
and may even suppurate. More frequently they become covered at the
edges or throughout by firm incrustations resulting from the drying of
the liquids thrown out, and the skin becomes increasingly thick and
rigid. A similar condition occurs behind the knee and in front of the
hock (malanders and salanders), and may extend from these points to the
hoof, virtually incasing that side of the limb in a permanent incrusting
sheath.

_Causes._--Besides a heavy lymphatic constitution, which predisposes to
this affection, the causes are overfeeding on grain, unwholesome fodder,
close, hot, dirty stables, constant contact with dung and urine and
their emanations, working in deep, irritant mud; above all, in limestone
districts, irritation by dry limestones or sandy dust in dry weather on
dirt roads; also cold drafts, snow, and freezing mud, washing the legs
with caustic soap, wrapping the wet legs in thick woolen bandages which
soak the skin and render it sensitive when exposed next day, clipping
the heels, weak heart and circulation, natural or supervening on
overwork, imperfect nourishment, impure air, lack of sunshine, chronic
exhausting, or debilitating diseases, or functional or structural
diseases of the heart, liver, or kidneys. These last induce dropsical
swelling of the limbs (stocking), weaken the parts, and induce cracking.
Finally the cicatrix of a preexisting crack, weak, rigid, and
unyielding, is liable to reopen under any severe exertion; hence rapid
paces and heavy draft are active caus