4 
Colorado Experiment Station. 
fected area at this time seems to be confined to the eastern portion of 
Colorado and extends from about 50 to 75 miles north of Denver to 
as far south as-Pueblo. The most thickly populated districts of this 
territory, as Denver and its vicinity, have the most cases. 
The beginning of this investigation was on August 31, 1908, when 
a call came from Greeley, where several cases had been diagnosed as 
rabies among dogs, cattle, etc., In this investigation the disease was 
studied in one horse, two cattle, and eight dogs. This covered a period 
of less than six months. Laboratory findings were confirmed by repeat¬ 
ed animal inoculations. Several people bitten by rabid dogs were ad¬ 
vised to proceed to a Pasteur Institute and take anti-rabic treatment. 
The mayor and city council upon receipt of an official report that rabies 
existed in that city, enforced a muzzling ordinance. All dogs on the 
highways not muzzled were destroyed. The result of this proceedure 
was that rabies was stamped out of Greeley. 
Later a typical case was received from Loveland. In a few weeks 
two cases came from Longmont, and about ten months later a third 
case. This last, a dog, had bitten another and in thirty-five days the 
dog ..bitten developed rabies. One case has been received from Fort 
Lupton, one from Platteville, and three from Castle Rock. Two se¬ 
rious outbreaks of rabies, due to stray rabid dogs, have occurred with¬ 
in the past few months near Denver. 
Since September, 1909, forty-three animals or their heads have 
been received at this laboratory from Denver. All but one head were 
from suspected eases of rabies. Of these heads two were from cattle, 
one cat, one wolf and the balance from dogs. Of these heads the brain 
of one was in a state of puterfaction and could not be examined and 
six did not show lesions of rabies. The balance, including two heads of 
cattle, showed lesions of rabies. 
Animals Affected. 
All animals may develop rabies when bitten by one that is rabid. 
This includes horses, cattle, sheep, hogs, dogs, cats, pole cats, mice, 
wolves, man, etc. 
Tra nsmissib ility. 
So far as has been proven the disease is only transmitted by the 
bite of a rabid animal or by inoculation. 
Virulency of the Saliva. 
The virus may be introduced into an already existing wound 
through holding an autopsy, or by the animal licking a wound. It 
is usually done by the bite of a rabid animal. By careful experiment 
it has been found that the saliva of a dog may contain the virus for 
seven or eight days before developing symptoms of the disease. As 
the virus is contained in the saliva, the teeth inflicting the wound carry 
the infection and deposit it in the wound. 
It is a mistake to hasten to kill a suspected dog. The symptoms, 
if any, should be noted, and later, if rabies is diagnosed, the dog may 
be killed, and if desired, the head sent to the laboratory for micros¬ 
copic examination. 
