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

A guinea pig is pregnant for about 68 days, roughly 2 months and 1 week. Normal birthing happens between 59 and 72 days, and a typical litter is 2-4 pups.

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:

Guinea pig gestation timeline from day 0 to day 68: day 15 Pregnancy usually confirmable by gentle palpation or ultrasound; day 21 Switch to unlimited alfalfa hay for extra calcium and protein; day 35 Stop picking her up unless necessary; support the hindquarters if you must; day 45 Pups become visible and their movement can be seen from outside; day 56 Pelvic separation begins — check gently once a day; day 63 Earliest normal birth; separate the boar now if he is still present; day 68 Expected birth.

Guinea pig gestation stages, month by month

Days 1–20: early pregnancy

Nothing is visible from outside. A vet can often feel the pregnancy by gentle palpation from about day 15. Keep the cage routine unchanged, keep vitamin C intake high with fresh greens and peppers, and start moving her onto alfalfa hay alongside her grass hay.

Days 21–45: growth becomes obvious

She will gain weight quickly — weigh her weekly, as steady gain is the best evidence everything is going well. Unlimited alfalfa hay and fresh pellets cover the extra calcium and protein. By day 45 you can usually see the pups moving under her flanks.

Days 46–60: late pregnancy

She may become nearly as wide as she is long and struggle to reach food, so put hay, pellets, water and greens where she can reach them without climbing. Handle her as little as possible and never lift her without supporting the hindquarters. Watch appetite obsessively: going off food here means pregnancy toxaemia.

Days 61–72: birth

The pubic symphysis separates to about a finger's width one to two days before birth — this is the most reliable predictor. Birth itself is fast, often 30 minutes for the whole litter, and she cleans and nurses the pups immediately. Pups nibble solids on day one and are weaned by three weeks.

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.

Estimate your guinea pig's birthing date

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

Estimate a guinea pig due date

Breeding date

Estimated birthing date

Thursday, 19 November 2026

Earliest

10 Nov 2026

Latest

23 Nov 2026

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Guinea pig pregnancy FAQs

How long is a guinea pig pregnant?

About 68 days, with a normal range of 59 to 72 days. Small litters of one or two pups tend to arrive around 70 days and large litters of four or more around 63.

Why is guinea pig gestation so much longer than other rodents?

Because guinea pigs are precocial — the pups are born fully furred with open eyes and teeth, able to walk and eat solid food within a day. That development happens in the uterus, so it takes nine to ten weeks instead of three.

What is pregnancy toxaemia and how do I avoid it?

It is a metabolic crisis in the last two weeks of pregnancy, most common in overweight sows and after any interruption to feeding. Keep her eating constantly, keep her weight sensible before breeding, avoid all stress and heat, and treat refusal of food as a same-day emergency.

How can I tell birth is close?

Feel gently just in front of the genitals: the two halves of the pelvis separate to roughly a finger's width one to two days before the birth. Guinea pigs do not nest or behave dramatically, so this pelvic check is the only real warning you get.

When must the boar be separated?

Before the birth. A sow can be mated and conceive again within hours of delivering, so leaving the boar in means back-to-back pregnancies that seriously damage her health.

Is it dangerous to breed a guinea pig for the first time when she is older?

Yes. If a sow has never been pregnant before about seven months of age, her pubic symphysis fuses and cannot separate properly for birth, which makes a difficult delivery and a caesarean much more likely.

More gestation pages

Rodent gestation periods