anifest by the formation of circular patches on the
skin, which soon becomes denuded of hair. The cuticular layer of the skin
in slightly inflamed, and vesication with exudation occurs, followed by the
formation of scaly, brittle crusts. The patches appear silvery gray when
incrusted, and are mostly confined to the head and neck. It is a common
disease among young cattle in the winter and spring. Very early in the
development of the patches the hairs split, twist, and break off close to
the skin. This disease is attended with more or less itching. It is
communicable to man.

Tinea favosa comes from another fungus, the _Achorion schoenleinii._ This
enters the hair follicle and involves the cuticle surrounding it, small
crusts form which increase in diameter and thickness and then become
elevated at their margin, forming a cup-shaped scab, the favus cup, which
gives the disease its distinctive character. The number of these cups
varies from a few to many hundreds. The hairs involved become brittle and
broken, fall off with the crusts, leaving small bald patches. The crusts
are of a pale or sulphur-yellow color at first; as they grow older they
turn darker, or to a brown color. This form of ringworm has a peculiar
odor, resembling that of mice or musty straw. It is occasionally
communicated to cattle by man, mice, cats, etc., all being subject to it.

_Treatment._--Remove all crusts by washing with soap and water, then apply
acetic acid, sulphur ointment, tincture of iodin or nitrate of mercury
ointment once a day. Cleanse the stable and whitewash it to destroy the
spores scattered by the crusts.

OTHER PARASITES AND PARASITIC DISEASES OF THE SKIN.

For discussion of mange, itch, scab, lousiness, warbles (grub in the skin),
buffalo gnats, hornfly (_Hoematobia serrata_), ticks, flies, etc., see the
chapter on "The animal parasites of cattle," page 502.

WOUNDS OF THE SKIN.

SNAKE BITES AND VENOMOUS STINGS.

[See discussion of these subjects in chapter on "Poisons and poisoning."]

BURNS AND SCALDS.

This is a rare accident among cattle, yet in cases of fire it may occur.
The application of heat, whether dry or moist, unless sufficient instantly
to destroy the life of a part, is always followed by the development of
vesicles or blisters, which contain a thin, watery fluid. The blisters may
be isolated and not very large, or one blister may cover a very large
surface. When the burn is very severe the skin may