39263—-B 
The Peruvian or long-haired guinea pig. 
usually about 2 ounces lhghter than 
males. Guinea pigs have lived past 
7 years of age. 
BREEDING 
Guinea pigs are prolific, and it 
isn’t difficult to build up a sizable 
herd within a year or two. 
Female guinea pigs (sows) be- 
come sexually mature 30 to 45 days 
after birth and will breed at this 
age. Estrus occurs every 14 to 17 
days and lasts about 24 hours. 
Male guinea pigs (boars) become 
sexually mature about 60 days after 
birth. Remove those not to be used 
for breeding when 40 to 50 days old 
and place them in separate pens. 
The gestation period of the guinea 
pig lasts 65 to 70 days, and a vigor- 
ous sow may give birth to four or 
five litters a year. The average litter 
contains three young, but some 
litters contain five or more. 
The female comes into heat im- 
mediately after giving birth and 
usually mates within 10 to 12 hours. 
To insure regular mating, place 
the female in the same pen as the 
breeder male at this time. 
Guinea pigs produce young until 
they are 3 years old, and may con- 
tinue to breed until the age of 5. 
HEALTH 
When laboratory guinea pigs de- 
velop a rough coat, lack appetite, 
or lose weight rapidly, a disease is 
probably the cause. Because many 
of the symptoms of diseases that 
affect guinea pigs are similar, even 
a trained person may have difficulty 
in distinguishing one disease from 
another. Your veterinarian can 
recommend the best measures to 
control and eradicate disease. 
Sulfa drugs or antibiotics can be 
used in treating most infectious 
diseases of guinea pigs. These drugs 
should be used as approved by the 
Food and Drug Administration and 
only with professional advice; in- 
correct dosages can injure your 
animals. 
With some diseases, the best pro- 
cedure is to dispose of the infected 
or exposed animals promptly and 
humanely. Burn the carcasses or 
bury them deeply. Burn all refuse 
and disinfect the animals’ pens. Use 
