2. Pregnant Guinea Pig Signs
• Weight gain after 2+ weeks
• Increase in food and water intake
• Mood changes due to rise in hormone level
• Increase in fatigue, resulting in more sleeping and/or change in
sleeping pattern
• Noticeable enlargement of nipples
3. Gestation Period
• The gestation period is between 59-72 days, with an average
pregnancy of 65 days.
• Duration of guinea pig pregnancy depends on the number of pups:
the larger the litter the shorter the pregnancy.
• Litter size ranges, with the average being 2-4 pups – in rare cases as
many as 12-14.
4. Care of Newborn
• Newborn guinea pigs weigh about 3.5 ounces (100 g). Even at such a
small size, they have hair and are able to see and run. They will nurse
from their mother but are able to nibble at solid food (such as
moistened pellets) within 2 days. The mother has a single pair of
mammary glands from which the newborns will nurse until about 3
weeks of age. When they reach about 6 ounces (170 g), the offspring
will stop nursing and eat the same foods as their parents.
• It is important to begin to carefully handle young guinea pigs when
they are only 2 or 3 weeks old. This is the period when young guinea
pigs will develop bonds with humans and learn to accept being held.
5. Weaning
• Pups are usually weaned at 21 days (3 weeks) but milk
supplementation can continue up to 4 weeks. Hay, guinea pig pellets
and very small amounts of vegetables can be offered from birth.
Young guinea pigs will watch adults eating to learn what is safe.
6. Guinea Pig Size Chart
• Age Size
• Birth 8-10 cm (3-4 inches)
• 8 Weeks 15-20 cm (6-8 inches)
• 16 weeks 20-25 cm (8-10 inches)
• 14 months 20-30 cm (8-12 inches)
