Breeding should be done in a responsible, well informed manner and viewed as a commitment to the resulting offspring as well as the parents. Only purchasing guinea pigs from reputable breeders or rescues goes a long way towards promoting good guinea pig care. Whilst conditions inside pet shops are improving greatly the same cannot always be said of their suppliers. Contact your local rescue for more local information. Obtaining guinea pigs from the internet is promoting selling in an environment that, as yet, has no control, though these issues are being looked into.

The R.S.P.C.A. recommend that guinea pigs are purchased from their breeder (a reputable one) or from a reputable rescue centre.

Young pigs are known as Pups or more affectionately as Mini Pigs. They are born fully furred and mobile. In order to be this advanced at birth the gestation period is comparably long to that of other small mammals that give birth to their young in nests protected by burrows. Guinea pigs would be born on the plains protected on by the undergrowth and their ability to flee danger. Their eyes are fully open.

The sow should be well after the birth and have a keen appetite, those that look listless or unwell are likely to have had a complicated birth.

  • The birth weight can range from 30-100g+
  • Litter size is from 1-8 although 10 has been recorded.
  • Gestation period: approximately 63-70 days
  • Post partum fertile: Yes, for 2-15 hours (boars should be removed before the birth to prevent unwanted pregnancy).
  • Estrus cycle: 15-17 days long, the sow is receptive to the boar for mating for approximately 12 hours.
  • Weaning age: Generally 14-21 days old the pups will stop nursing.
  • Sows fertile from 4-6 weeks of age.
  • Boars fertile from 3-6 weeks of age. Separate them from their mother and sister(s) at 3 weeks of age to prevent pregnancy.

Pups that are born weak or with ‘complications’ can make remarkable progress within a few days with little interference. The sow can usually sense when a pup is weak and will concentrate her efforts on the others.