Guinea Pig Gestation Calculator

Guinea pig pregnancy runs long for a rodent, usually about 59 to 72 days, because the pups are born fully developed. Enter the breeding or exposure date above for a due window, then use the facts below to plan ahead. None of this replaces hands on guidance from your veterinarian.

Guinea pig gestation at a glance

The figures below are typical averages; every sow is different, so treat them as planning guides rather than guarantees.

• Average length: 68 days
• Typical range: 59 to 72 days
• Litter size: 1 to 6 pups
• Common litter: 2 to 4 pups
• Pups born: fully furred
• Eyes: open at birth
• Weaning age: about 21 days
• Heat cycle: roughly 16 days
• First breeding: before 6 months
• Female name: sow
• Male name: boar
• Baby name: pup

Signs a sow is close to farrowing

Guinea pigs give little warning, so watch quietly and keep your vet number handy.

• Widening pelvis
• Pear shaped belly
• Reduced appetite
• Restlessness
• Nesting in a corner
• Seeking quiet
• Firm belly movement
• Weight gain slows
• Straining begins
• Pups arrive quickly
• Sow eats afterbirth
• Pups nurse within hours

Frequently asked questions

How long are guinea pigs pregnant?

Guinea pig gestation averages about 68 days and usually falls between 59 and 72 days. That is unusually long for a rodent, and it is why pups are born fully furred with open eyes and able to nibble solid food within a day or two.

How many pups are in a guinea pig litter?

Most litters are 2 to 4 pups, though a sow can have anywhere from 1 to 6. First litters and litters from young sows tend to be smaller. A single large pup can be harder to deliver, so any sow straining without progress should see a vet promptly.

Why should a sow have her first litter before six months?

The pelvic bones fuse as a sow matures, and if she has never given birth by roughly six to seven months of age the birth canal may not open enough for a safe delivery. Breeders time a first litter earlier to lower this risk, but the timing decision is best made with your veterinarian.

What are the warning signs of pregnancy toxemia?

Late pregnancy toxemia is a serious risk, especially in overweight sows or after a stress or feed change. Warning signs include a sudden drop in appetite, low energy, and muscle weakness. It can be fatal quickly, so contact your veterinarian at the first sign rather than waiting.