eumatism may
be mentioned exposure to dampness and cold, especially while the animal is
perspiring or fatigued after severe physical exertion. Among other causes
often mentioned are acidity of the blood, nervous derangement, microbes,
and injuries. It occasionally follows another disease, such as pleurisy.
The influence of age and heredity may be considered as secondary or
predisposing causes. Sometimes the disease appears without any apparent
cause. On the whole, it may be said that any of the above-mentioned factors
may have more or less influence on the production of rheumatism, but the
specific cause is as yet unknown.

_Symptoms of articular rheumatism._--The symptoms appear suddenly and with
varying degrees of severity. The animal presents a downcast appearance,
with staring coat, horns and ears cold, and the mouth and muzzle hot and
dry. Appetite and rumination may be impaired and followed later or be
accompanied at the same time by constipation. Constipation may be followed
by impaction of the stomach or bowels. Thirst is increased, but the amount
of urine voided is scanty. Respiration and pulse are accelerated, and there
is usually a fever, rising sometimes as high as 108 deg. F. The animal prefers
to lie down, and when forced to rise stands with its back arched. The
movements are stiff and lame and cause great pain. The disease may attack
one or more joints at the same time; in fact, it is often symmetrical. One
joint may improve while another becomes affected, thus showing the shifting
tendency of the inflammation. The affected joints, including their tendons,
ligaments, and synovial membranes, may be swollen, hot, and distended with
liquid. They are very tender, and, if treated carelessly or injured, may
become infected, thus leading to suppuration. While rheumatism attacks
perhaps more frequently the knees and fetlocks, it has no special affinity
for any joint and may attack the stifle, hip, shoulder, or elbow joint. In
mild cases of articular rheumatism, the animal may fully recover in a few
days.

In chronic articular rheumatism there is less tendency of the disease to
shift about, but there is a greater liability of structural change in the
affected joints. This change may consist of induration, exostosis, or even
anchylosis. These structural changes about the joints may lead to permanent
deformity, such as the bending of the neck. Fever is not so constant in the
chronic form as in the acute, and the lat