This common disease seems to differ sufficiently in its characteristics
to warrant a distinction into two species. In one it appears to be
caused by an obstruction of the air-cells, by an accumulation of phlegm,
which interferes with the exercise of their functions. The fowl labors
for breath, in consequence of not being able to take in the usual
quantity of air at an inspiration. The capacity of the lungs is thereby
diminished, the lining membrane of the windpipe becomes thickened, and
its minute branches are more or less affected. These effects may,
perhaps, be attributed to the fact that, as our poultry are originally
natives of tropical climates, they require a more equal temperature than
is afforded, except by artificial means, however well they may appear
acclimated.
Another variety of asthma is induced by fright, or undue excitement. It
is sometimes produced by chasing fowls to catch them, by seizing them
suddenly, or by their fighting with each other. In these cases, a
blood-vessel is often ruptured, and sometimes one or more of the
air-cells. The symptoms are, short breathing; opening of the beak often,
and for quite a time; heaving and panting of the chest; and, in case of
a rupture of a blood-vessel, a drop of blood appearing on the beak.
_Treatment._ Confirmed asthma is difficult to cure. For the disease in
its incipient state, the fowl should be kept warm, and treated with
repeated doses of hippo-powder and sulphur, mixed with butter, with the
addition of a small quantity of Cayenne pepper.