If you think your guinea pig might be pregnant, here are some things to consider as you take care of her during her pregnancy.
Facts to Know
- Female guinea pigs (sows) can get pregnant once they reach 4-6 weeks old.
- A male guinea pig (boar) can impregnate a female once he reaches 3-5 weeks old.
- A pregnant female can get pregnant again right after she gives birth (which is SO not a good idea!)
- Pregnancy can be hard on guinea pigs. There are statistics showing that 20% of pregnant guinea pigs die or have serious complications resulting from pregnancy.
- A guinea pig stays pregnant for about two months. Pregnancy can last from 58-72 days, and the average is about 65 days.
- Baby guinea pigs will wean after 2-3 weeks.
- Guinea pigs can give birth to anywhere from 1 to 9 pups. The average litter size is around 3-4 pups, but it varies depending on how old she is, how many pregnancies she’s had, and how close together her pregnancies are.
How to Tell if Your Guinea Pig is Pregnant
At the beginning of a guinea pig pregnancy, you won’t be able to tell if your female guinea pig is pregnant or not.
However, if she’s at least 4 weeks old and has been around a boar (boy) who is at least 3 weeks old, there’s a pretty good chance she could be pregnant!
One of the first hints of a guinea pig pregnancy is that she will eat and drink more. As the pregnancy progresses, the amount of food and water intake will likely increase.
However, eating and drinking more isn’t a definitive pregnancy diagnosis! Guinea pigs can up their food and water intake if it’s cold, if it’s too hot, or when they have certain illnesses. But it’s one signal you can look for.
Of course, you could take your guinea pig to a vet. They can give you a definitive diagnosis right away.
After the second week, though, you should be able to feel the babies in her uterus. You certainly don’t want to grab her and squeeze to try to find out! But you can gently feel around in a circular motion with your thumb for lumps and bumps.
Once again, feeling lumps and bumps isn’t a definitive diagnosis by itself, since there are other reasons for lumps and bumps, like tumors and cysts. If you feel lumps, and you still don’t know if she’s pregnant, be sure to take her to a vet and get those checked.
If she’s not so young that she’s still growing, you can check her weight weekly to see if she’s gaining weight, as well. During the course of pregnancy, her weight can double! A normal, non-pregnant guinea pig weighs about 1.6 pounds, and at full term, a pregnant guinea pig can weigh between 2.2 – 3 pounds.
One of these symptoms may or may not indicate pregnancy, but taken together, you can probably figure out if your guinea pig is pregnant if she has two or more of the indicators mentioned. To recap:
- She’s older than 4 weeks and has been around a boar that’s at least 3 weeks old
- She’s eating or drinking more than normal
- She’s bigger around the abdomen or gaining weight
- You can feel bumps in her abdomen
- And of course, a vet tested her and told you so!
Developmental Milestones in a Guinea Pig Pregnancy
Here are some developmental milestones during a guinea pig’s pregnancy:
- The heartbeat of a guinea pig fetus can be detected at about day 5.
- The kidneys of the fetuses can be seen on scans starting on Day 35 of the pregnancy.
- You can see the fetus’ crown rumps on scans starting at Day 15 of the pregnancy.
Interesting Facts about Female Guinea Pig Anatomy
- Female guinea pigs have two uterine horns, and each horn provides space for one to five implantation sites.
- Guinea pigs have a placenta that is pretty similar to the human placenta (with regard to how it functions), but guinea pigs also have a separate sub-placenta and a yolk sac placenta (which humans don’t have).
- Here’s an illustration showing the uterus of a pregnant guinea pig from the of California San Diego:
How to Take Care of Your Pregnant Guinea Pig
Pregnant guinea pigs are pretty good at taking care of their own needs, but there are things to keep in mind to help you take care of her during this time:
- Make sure she has plenty of fresh water available at all times, as well as plenty of food and hay.
- Her Vitamin C needs will increase, so make sure she gets at least 30-40 mg of Vitamin C a day during the pregnancy. You can use the Vitamin C calculator to help determine how much she is getting based on her daily food intake.
- There shouldn’t be a problem giving your guinea pig enough copper and iron, but it is worth mentioning that if a pregnant guinea pig eats less than 1 mg of copper per kilogram of body weight during pregnancy, the pups will have “growth retardation, cardiovascular defects, and severe abnormalities of the central nervous system including agenesis of cerebellar folia, cerebral edema, and delayed myelination” (Everson et al., 1968).
- Speaking of other trace elements, if the female doesn’t get enough zinc in her diet (less than 2 mg Zn/kg) during pregnancy, it can result in premature delivery or abortion (Apgar and Everett, 1991b).
So, be sure you’re giving her plenty of high-quality pellets, fresh veggies, and grass hay. During pregnancy, she needs a bit more calcium, too, so you can feed alfalfa hay or pellets that contain alfalfa.
Getting Ready for Birth
When your guinea pig gives birth, she will prefer a sheltered, private, cozy place to have her pups.
Make sure you have a phone number for a vet who has experience with guinea pigs. If you notice any signs of distress or problems during the birthing process, you want to be able to call them right away – even if it’s not business hours. So, have a vet’s number ready and talk to them about their after-hours policy.
Typically, your guinea pig will get through the birthing process relatively quickly (in under 45 minutes, usually), so there’s a chance that it will happen and be done before you even notice!
After she gives birth, she needs to eat the afterbirth. This helps trigger her uterus contractions and stimulate oxytocin and prolactin release, so leave her alone (as long as there aren’t any problems to attend to) and let her do what she needs to do.
Fear and stress can stop her from being able to produce milk, so keep her environment as stress-free as you can.
Just monitor her and make sure she’s not having any trouble breathing, that there isn’t any excessive salivation happening, and that there isn’t any excessive bleeding. Always remember, if you have any doubts whatsoever, call that vet!