CHAPTER VI.
HOG-CHOLERA.

bacillus of hog-cholera (Bacillus suipestifer) was
first found by Salmon and Smith/ but was for a long time
confused with the bacillus of " swine-plague," which it
closely resembles and with which it frequently occurs.
It is a member of the group of which the Bacillus coli
communis may be taken as a type. Since the careful
studies of Smith,1 however, the claims of the discoverers
that the bacillus of hog-cholera is a separate and specific
organism can hardly be doubted.

Hog-cholera, or upig typhoid," as the English call it
is a common epidemic disease of swine, which at times
kills 90 per cent, of the infected animals, and thus causes
immense loss to breeders. Salmon estimates that the
annual losses from this disease in the United States
range from $10,000,000 to $25,000,000.

The disease is particularly fatal to young pigs. The
symptoms are not very characteristic, and the animals
often die suddenly without having appeared particularly
ill, or after seeming ill but a few hours. The symptoms
consist of fever (io6°-iO7° F.), unwillingness to move,
and more or less loss of appetite. The animals may ap-
pear stupid and dull, and have a tendency to hide in the
bedding and remain covered by it. The bowels may be
normal or constipated at the beginning of the attack,
but later there is generally a liquid and fetid diarrhea,
abundant, exhausting, and persisting to the end. The
eyes are congested and watery, the secretion drying and

1 Reports of the Bureau of Animal Industry, 1885-91.

2 Centralbl fur Bakt. und Parasitenk., Bd. ix., Nos. 8, 9, and 10, March
2, 1897.

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