rangles at a somewhat
earlier age than those of more humble origin. Mules and asses are much
less susceptible and are but rarely affected. Other animals are not
subject to this disease, but there is a certain analogy between it and
distemper in dogs. After exposure to infection there is a period of
incubation of the disease, lasting from two to four days, during which
the animal enjoys its ordinary health.

_Symptoms._--The horse at first is a little sluggish if used, or when
placed in its stable is somewhat dejected, paying but moderate attention
to the various disturbing surroundings. Its appetite is somewhat
diminished in many cases, while in some cases the animal eats well
throughout. Thirst is increased, but not a great deal of water is taken
at one time. If a bucket of water is placed in the manger the patient
will dip its nose into it and swallow a few mouthfuls, allowing some of
it to drip back and then stop, to return to it in a short time. The coat
becomes dry and the hairs stand on end. At times the horse will have
chills of one or the other leg, the fore quarters, or hind quarters, or
in severe cases of the whole body, with trembling of the muscles and
dryness of the skin.

If the eyes and mouth are examined the membranes are found reddened to a
bright rosy color. The pulse is quickened and the breathing may be
slightly accelerated. At the end of two days a cough is heard and a
discharge begins to come from the nostrils. This discharge is at first
watery; it then becomes thicker, somewhat bluish in color, and sticky,
and finally it assumes the yellowish color of matter and increases
greatly in quantity.

At the outset the colt may sneeze occasionally and a cough is heard. The
cough is at first repeated and harsh, but soon becomes softer and moist
as the discharge increases. Again, the cough varies according to the
source of the discharge, for in light cases this may be only a catarrh
of the nasal canals, or it may be from the throat, the windpipe, or the
air tubes of the lungs, or even from the lungs themselves. According to
the organ affected the symptoms and character of cough are similar to
those of a laryngitis, bronchitis, or lung fever caused by ordinary
cold.

Shortly after the discharge is seen a swelling takes place under the
jaw, or in the intermaxillary space. This is at first puffy, somewhat
hot and tender, and finally becomes distinctly so, and an abscess is
felt, or having broken itself th