Guinea pig Gestation Period: How Long Is a Guinea pig Pregnant?

How long is a guinea pig pregnant?

A guinea pig carries her pup for an average of 68 days, or about 2 months and 1 week. Counting from the breeding date, birthing is normal anywhere from day 59 to day 72.

Key checkpoints across the 68-day guinea pig gestation, measured in days from breeding:

Estimate your guinea pig's birthing date

Enter the breeding date for an estimated birthing date at 68 days.

Open the full Guinea pig gestation calculator

Guinea pig gestation stages, month by month

Signs a guinea pig is pregnant

• Steady weekly weight gain from about the third week, which is the most reliable early sign
• A vet can confirm by gentle palpation from around day 15 or by ultrasound
• Pear-shaped body from roughly day 35, becoming very wide by day 50
• Visible pup movement under the flanks in the last three weeks

Signs of approaching birthing

• The pelvis separates to about a finger's width one to two days before the birth
• She becomes quiet and settled rather than restless — guinea pigs build no nest at all
• Contact your vet if labour stalls, if the animal strains without progress, or if there is abnormal discharge before birthing begins.

What affects guinea pig gestation length

• Guinea pig gestation is unusually long for a rodent — about 68 days against 20 for a mouse — and the pups are born fully furred, eyes open, and able to eat solid food within a day.
• Litter size drives the due date more than anything else: a sow carrying one or two pups often goes to 70 days or beyond, while a litter of four or more usually arrives around 63 days.
• Pregnancy toxaemia in the last two weeks is the single biggest killer of pregnant guinea pigs, and it strikes overweight sows and sows that stop eating. Any pregnant sow that refuses food is an emergency.
• Dystocia is common in sows bred for the first time after about seven months of age, because the pubic symphysis fuses and can no longer separate for birth.
• A sow can conceive again within hours of giving birth, so the boar must be removed before the birth, not after.
• Guinea pigs cannot make their own vitamin C and requirements rise during pregnancy, so fresh peppers, leafy greens and fresh pellets matter more than usual.

Guinea pig gestation chart

Every fifth breeding date across the year with the matching birthing date, calculated at 68 days. Find the row closest to the date the guinea pig was served; because normal gestation spans 59 to 72 days, plan for a window of a few days either side. Filter by month, or print the chart for the barn wall or breeding record: navigation, buttons and adverts are hidden on paper.

Guinea pig gestation length by breed

Sources for guinea pig gestation figures

Figures on this page are drawn from exotic companion mammal veterinary texts, cavy breeder records and published guinea pig reproduction research, and checked against the references below. Averages describe healthy animals under normal management; individual animals vary, and nothing here replaces advice from your vet.

• Merck Veterinary Manual — reproduction and pregnancy chapters by species
• Laboratory animal science references on rodent reproduction