on 
RAISING 
GUINEA PIGS 
Before 1870, guinea pigs were 
kept exclusively as pets. Since that 
date, their use by Pasteur, Koch, 
and other scientists in experiments 
has established their value in study- 
ing disease symptoms of humans 
and animals. Because their reac- 
tions to different tests are now well 
known, guinea pigs are valuable in 
genetic studies, in analyzing the 
effects of drugs, in standardizing 
vaccines and serums, and in deter- 
mining the vitamin content of 
foods. 
DESCRIPTION 
The guinea pig is a quiet, gentle 
rodent with a short, stocky body, 
short ears, short legs, and no tail. 
Adult guinea pigs weigh about 134 
to 214 pounds; they are vegetarians, 
are relatively easy to keep, and 
breed rapidly. The principal types 
differ from one another in hair 
characteristics and color. All domes- 
ticated guinea pigs are descended 
from stock originally found in the 
Andes Mountains of Peru. 
A guinea pig’s hair may be 
smooth and short, rough and short, 
or silky and long. The short-haired, 
English variety of guinea pig is the 
most common. The coat of the Abys- 
sinian guinea pig is short and 
rough; the Peruvian variety is long- 
haired. Generally, the English guin- 
ea pig is the type used in labora- 
tory work and most successfully 
raised commercially. 
Most guinea pigs have solid col- 
ors—black, white, brown, red, tan, 
or gold. Some have hair of mixed 
colors, alternating in bands of light 
and dark fur. Others are character- 
ized by solid colors with white spots. 
Commercial breeders have devel- 
oped various colors and color com- 
binations. Guinea pigs with two or 
even three colors are not uncommon, 
BUYING AND SELLING 
Guinea pigs may be bought from 
pet stores or laboratory supply 
houses. For names of dealers and 
reference books, write to the Insti- 
tute of Laboratory Animal Re- 
sources, National Research Council, 
National Academy of Sciences, 2101 
Constitution Avenue NW, Wash- 
ington, D.C. 20402. There is no 
charge for this service. 
The Department of Agriculture 
does not purchase or sell guinea pigs 
and has none for free distribution. 
The Laboratory Animal Welfare 
Act requires commercial raisers of 
guinea pigs to obtain a license, pay 
an annual fee, and comply with the 
act’s provisions. Research facilities 
must register and acknowledge the 
act’s standards. For additional in- 
formation and a copy of this act, 
write to the Director, Animal 
Health Division, Agricultural Re- 
search Service, U.S. Department 
of Agriculture, Hyattsville, Md. 
20782. There is no charge for this 
service. 
Breeding guinea pigs are usually 
sold in pairs or in trios of one male 
and two females. These animals are 
usually more expensive than gen- 
eral laboratory stock. Producers of 
