PORK PRODUCTION FOR RURAL SCHOOLS. 
23 
dirty drinking and feeding troughs may be regarded as an indirect 
cause. 
Since the disease can only be started by the introduction of the 
germ into the herd, and the organism is always present in the bodies 
of sick hogs and is thrown off in the feces and urine, the most dan- 
gerous factor in spreading the disease is the sick animal. 
It may get into the herd by sick hogs escaping from a neighboring 
herd, by the purchase of new stock not showing symptoms, by re- 
turning show hogs after visits to fairs or stockyards, and by the 
purchase of hogs which apparently have recovered. 
Fig. 14.— Scrubbing and cleaning the part preparatory to injecting the serum. 
(b) The symptoms are not constant and uniform, therefore the 
disease can not always be diagnosed with absolute certainty. Ani- 
mals suffering from intestinal troubles, indigestion, and poisoning 
exhibit symptoms which closely resemble those of cholera. 
In the early stages, hogs huddle together; have high temperatures 
(105 to 107° F. or higher); are constipated; the feces often streaked 
with blood; a characteristic odor is present; and after the third or 
fourth day diarrhea develops. As death approaches there is usually 
a reddening of the skin on the under surface of the body, snout, and 
ears. This turns into a purple color if death is delayed a day or 
two. There is a discharge of mucus from the eyes. Coughing may 
or may not be present. In chronic cases there is emaciation, and 
patient may linger for days and weeks. 
