CHAPTER V.
CHICKEN-CHOLERA.

THE: barnyards of Europe, and sometimes of America,
are occasionally visited by an epidemic disease which
affects pigeons, turkeys, chickens, ducks, and geese, and
causes almost as much destruction among them as the
occasional epidemics of cholera and small-pox produce
among men. Rabbit-warrens are also at times seriously
affected by the epidemic. When fowls are ill with the
disease, they fall into a condition of weakness and apathy
which causes them to remain quiet, seemingly almost
paralyzed, and ruffle up the feathers. The eyes are
•closed shortly after the illness begins, and the birds
gradually fall into a stupor from which they do not
awaken. The disease leads to a fatal termination in
twenty-four to forty-eight hours. During its course
there is profuse diarrhea, the very frequent fluid, slimy,
grayish-white discharges containing numerous micro-
organisms.

The bacilli which are responsible for this disease were
first observed by Perroncito in 1878, and afterward thor-
oughly studied by Pasteur. They are short, broad bacilli
with rounded ends, sometimes united to each other,
with the production of moderately long chains (Fig. 112).
Pasteur at first regarded them as cocci, because when
stained with a penetrating anilin dye the poles stain
intensely, but a narrow space between them remains
almost uncolored. This peculiarity is very marked, and
sharp observation is required to observe the outline of
the intermediate substance. The bacillus does not form
spores, and does not stain by Gram's method. When

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