Pregnancy – the pregnant guinea pig

Baby guinea pigs are delightful, but pregnancy can carry risks and it is important to be aware of these and the care your guinea pig will require during her pregnancy.

Female guinea pigs can become fertile from as early as 4 weeks of age. For this reason it is very important that baby guinea pigs, known as pups, are sexed correctly at an early age, to avoid unplanned and potentially dangerous pregnancies. Guinea pigs can breed all year round but the highest proportion of births seems to occur in the spring months of the year. Guinea pigs can have 4 or 5 litters per year, each consisting of one to six pups, with an average of three, if their breeding is uncontrolled. Females can become pregnant 6–48 hours after giving birth, but it is not healthy for a female to be constantly pregnant.

For a rodent, guinea pigs have a long pregnancy. The gestation period lasts anywhere from 59-72 days with an average of 63-68. During this time the guinea pig will look noticeably larger.

If she lives with another female guinea pig they can stay together during the pregnancy and after she has given birth. If she is still with the male guinea pig it is best to separate them so she isn’t being pestered constantly, and to remove the risk of her getting pregnant again straight after giving birth.

Make sure she has a warm, enclosed and safe place to give birth in. If the weather is cold outside she will need moving indoors or into a shed or unused garage.

In the final weeks her food allowance should be increased due to the requirements the pups will place upon her.

You should offer a pregnant female plenty of fresh vitamin C rich vegetables as well as unlimited hay. Offer alfalfa hay too as this is high in calcium which is essential in pregnant sows. Do not overfeed pelleted diets as these can potentially cause larger pups which may prove difficult to pass.

Pups are born precocious, which means they are born fully furred with teeth, claws and partial eyesight. Within just a few minutes of birth they are able to scamper around and will begin eating solid food, as well as suckling from the mother.

In smaller litters, if the pups are oversized the mother may have difficulty giving birth and may require a caesarean section. Large litters usually result in a higher incidence of stillbirth.

Females who have their first litter after the age of 1 year may have difficulty giving birth, due to the ligaments within their pelvis being less mobile to be able to pass the young during birth. This can prove fatal for both the mother and pups. For this reason if a female is intended to be bred from she should have her first litter before this age.

Pregnancy toxemia can be fatal. Signs include anorexia, excessive salivation, lethargy and pear drop smelling breath (sweet smelling). If left to advance, the guinea pig will begin to seizure and death will occur.

Other complications of pregnancy which require urgent veterinary attention include a prolapsed uterus, hypocalcaemia (low blood calcium levels) and mastitis (a bacterial infection in the teats due to a build-up of milk).