INFLUENCE OF DISEASE UPON MILK 97 
and also to cattle and swine. It may also be transmitted 
by butter and cheese. Man may be mildly or severely 
affected; in some instances, the disease has terminated 
fatally. The symptoms are fever, weakness, conjuncti- 
vitis, nausea, vomiting, and diarrhoea, with formation of 
vesicles on the mucous membrane of the lips, mouth or 
nose, and on the ears, fingers or other places on the body; 
sometimes the skin is red and the joints painful. 
The sale of milk from herds in which foot and mouth 
disease exists should not be permitted, unless it is heated 
sufficiently to destroy the virus and is not changed in 
appearance. The virus is not very resistant. A tempera- 
ture of 50° C. (122° F.) for 15 minutes; 70° C. (168° F.) 
for 10 minutes; or 85° C. (185° F.) momentarily will 
destroy it (Ernst). 
COWPOX 
Cowpox is closely related to variola or smallpox of 
man. Before vaccination was introduced, when smallpox 
frequently became epidemic, it is very probable that cow- 
pox often originated from this source. Vaccinia of man is 
also transmissible to cattle and many instances are on 
record in which cows have been infected by vaccinated 
persons. Infection takes place during milking as a rule, 
the contagion being rubbed into the skin of the teat by 
the hands of the milker. The disease is therefore most 
commonly seen in cows in milk. It usually begins with a 
rise of temperature, but this may pass unnoticed unless 
it is accompanied by dullness and loss of appetite, as is 
sometimes the case. The teats and neighboring parts of 
the udder become swollen, hot, and painful. In two or 
three days, papules appear, which may be as large as a 
pea and which are surrounded by a red area. On the 
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