color. By auscultation, or placing the ear to
the sides of the chest, unnatural sounds can now be heard. The air
passing through the diseased tubes causes a wheezing sound when the
small tubes are affected, and a hoarse, cooing, or snoring sound when
the larger tubes are involved. After one or two days the dry stage of
the disease is succeeded by a moist state of the membrane. The ear now
detects a different sounds caused by the bursting of the bubbles as the
air passes through the fluid, which is the exudate of inflammation and
the augmented mucous secretions of the membrane. The mucus may be
secreted in great abundance, which, by blocking up the tubes, may cause
a collapse of a large extent of breathing surface. Usually the mucus is
expectorated; that is, discharged through the nose. The matter is
coughed up, and when it reaches the larynx much of it may be swallowed,
and some is discharged from the nostrils. The horse can not spit, like
the human being, nor does the matter coughed up gain access to the
mouth. If in serious cases all the symptoms become aggravated, the
breathing is labored, short, and quick, it usually indicates that the
inflammation has reached the breathing cells and that catarrhal
pneumonia is established. In this case the ribs rise and fall much more
than natural. This fact alone is enough to exclude the idea that the
animal may be affected with pleurisy, because in that disease the ribs
are as nearly fixed as it is in the power of the animal to do so, and
the breathing is accomplished to a great extent by aid of the abdominal
muscles. The horse persists in standing throughout the attack. He
prefers to stand with head to a door or window to gain all the fresh air
possible, but if not tied may occasionally wander listlessly about the
stall. The bowels most likely are constipated; the dung is covered with
slimy mucus. The urine is decreased in quantity and darker in color than
usual. The animal shows more or less thirst; in some cases the mouth is
full of saliva. The discharge from the nose increases in quantity as the
disease advances and inflammation subsides. This is rather a good
symptom, as it shows that one stage has passed. The discharge then
gradually decreases, the cough becomes less rasping, but of more
frequent occurrence, until it gradually disappears with the return of
health.

Bronchitis, affecting the smaller tubes, is one of the most fatal
diseases, while that of the larger tubes is