The best thing is to take your guinea pig to your vet for a pregnancy diagnosis. They can diagnose a pregnancy in various ways depending on how long your guinea pig has been pregnant. Some vets can do ultrasound exams to visualise babies in the womb. In later gestation vets may be able to take an xray or gently palpate the babies. They may be able to feel or see the babies moving. They may also be able to hear the babies’ heart beats in the mother’s abdomen.
There are vets who specialise in exotic animal medicine and surgery, including guinea pigs: your local vet can refer you to a guinea pig vet if necessary.
How long is a guinea pig pregnancy?
The guinea pig pregnancy duration is long – approximately 59- 72 days (the average is 65 days) – the duration decreases with litter size (i.e. the smaller the litter, the longer the pregnancy). The mean length of pregnancy for a litter of 1 guinea pig is 70 days; for a litter of 6 guinea pigs its 67 days. First litters tend to be smaller than subsequent litters. Females do become very big during pregnancy.
Determining the presence of babies is important. It is also important to determine the number of babies in the womb so that you can be sure the mother has given birth to all the babies and is not having difficulties delivering them all (helps to ensure no babies have remained stuck in the womb).
What should I feed my pregnant guinea pig?
Pregnant guinea pigs should be fed a mixed diet consisting of:
- grass and/or grass hay
- green leafy vegetables
- small amount of vitamin C rich foods e.g. citrus or kiwi fruit
- a small amount of high quality commercial pellet
- a small amount of lucerne hay – though this is not essential (as a supplement to provide increased calcium and protein)
General information on feeding guinea pigs is provided in the Knowledgebase article What should I feed my guinea pigs? Any changes to the existing diet should be made gradually to avoid stress or gastrointestinal upset which may affect the pregnancy.
How easy is the birth?
Difficulty giving birth is quite common in guinea pigs so it’s important to see your vet for further advice about care of pregnant guinea pigs and the birthing process. While some guinea pigs can give birth naturally and unassisted, others need veterinary help to give birth (some may require medications and/or a caesarean section).
You will need to determine with your vet when your guinea pig is likely to give birth and to observe her closely to ensure she receives veterinary help should there be any problems.
Pregnancy toxaemia (pregnancy ketosis)
This is a potentially fatal condition seen in some pregnant guinea pigs during late pregnancy or within a few days of giving birth. The predisposing factors include obesity (>800 grams), fasting (not being fed adequately), if it is the first or second pregnancy, change in diet, stress, and heredity.
The signs of pregnancy toxaemia are abrupt onset of depression (quiet, weak, lethargic) and anorexia (not eating). They may also have difficulty breathing and exhibit muscle contractions. Risk reduction includes preventing obesity in the mother guinea pig and providing adequate energy in the diet late in gestation. Some specialists recommend adding a small amount of glucose to the mother’s drinking water in late pregnancy as a preventive measure (please consult your vet about this first).
After the birth
Young guinea pigs begin eating solid food during the first few days post-birth. Weaning is a gradual teaching process which occurs over a period of time (approximately a few weeks). Babies must be kept with their mother until the weaning process has finished, the babies can feed independently and they are at least 4 weeks of age. Newborn guinea pigs are sexed by examining the external genitalia (your vet can assist in sexing the babies).
Guinea pigs reach sexual maturity early. Females can reach sexual maturity as early as approximately 4-6 weeks of age and males as early as approximately 8-9 weeks of age so the different sexes should be separated before they are able to reproduce with each other. Note above that babies must be kept with their mother until the weaning process has finished and they are able to feed independently.
Guinea pigs can fall pregnant again straight after giving birth to their litter – so entire adult males must be kept separately from females in late pregnancy and after the birth to prevent any further unwanted/unplanned litters of baby guinea pigs.