Although initial signs of pregnancy are difficult to detect, Loving Your Pet explains that pregnant guinea pigs drink more water and grow larger; however, pregnancy cannot be confirmed until the latter stages when her young can be felt through her skin. Guinea pigs prefer to give birth at night, labor lasting between 15 to 40 minutes, says Guinea Lynx. They often eat the afterbirth and placenta, hiding all evidence of a messy delivery.
Although guinea pigs typically have very easy pregnancies, complications can arise before and during labor. If a sow smells like nail polish or acetone anytime between two weeks before to two weeks after giving birth, Guinea Lynx recommends contacting a veterinarian. Lethargy, vaginal discharge and drooling during pregnancy should be reported to a vet immediately. A pregnant sow can stay with other females or a boar up to one week before delivery. Squealing and blood during labor are also warning signs that the sow is having problems. Although some sows may take up to a day to accept and care for the new litter, attacking and biting are bad signs, and the mother must be removed immediately. If the sow displays any kind of symptoms of illness post-pregnancy, she should be taken to the veterinarian.