You are here:

Guinea Pigs/pregnant guinea pig??


Hi! I have a guinea pig that i suspect to be pregnant, she would be at almost five weeks now. I'm just not sure if she is and was wondering if you could give me your opinion. She gained a lot of weight right away after mating and i thought i noticed her hips expanded as well. She seems to be bigger on one side of her body which made me think maybe she's carrying more pups on that side.but today i noticed her vagina looks slightly redder and she is acting hyper with her female cage mate trying to push her around. I'm afraid maybe this is her in great and she's not pregnant after all? What do you think? I could send a picture if that would help.

Since a cavy's gestation is 10 weeks they don't always show that much half way through pregnancy. I'm glad to made comment of the mite problem. That's the first thing my eye was drawn to by the picture.

The redness in the area of the vent may well mean she's in heat again. Her behavior sounds very much like she is, with the crabby behavior and hyperactivity. It's very difficult to pinpoint the moment of conception since they're only in heat for a few days and only receptive for a few hours of that time. That doesn't mean it's not impossible, just unlikely.

If she is larger on one side than the other that could mean something entirely different than pregnancy.

The concern is ovarian tumors, which typically show a lopsided growth appearing much like pregnancy. They're not uncommon in guinea pigs. They're seldom malignant and the only issue is the out of control hormones. Most pigs with ovarian tumors manage to live with them without any bad side effects. The cost of surgery to remove a tumor is not cheap, so most owners simply choose to let the condition go.

If she is pregnant you should start feeling movement about two or three weeks from now. That will be the defining diagnosis. It's unusual for a weight gain right after mating. The signs of pregnancy don't always appear until the last month. I she is over two and has been bred before she may just have what we call a 'potty' shape, much like we get as we age.

At this point it's just a wait and see thing that time will tell. Treating her for mites is safe during her pregnancy if you are using Ivermectin paste, but not while she's nursing pups.

I hope this helps you out. If she is pregnant I would love to see pictures of the babies when they come.

Guinea Pigs

All Answers

Answers by Expert:

Ask Experts


Pat VanAllen


As is sometimes the case, people in urgent need of information have a higher degree of expectation than those of us as experts are able to give. The experts on this site do their best to give the most accurate and responsible answers possible. We ask that you remember that it is not our intention nor place to criticize the professional advice given by your veterinarian, nor is it appropriate for us to comment on the correctness of a diagnosis made by a licensed physician. Our knowledge is experience based. Although many years of breeding and showing cavies gives me a wealth of experience it cannot change the fact that we as experts are not veterinarians and therefore may occasionally have to reject questions that appear to be asking us to criticize advice given by the licensed professional. Having raised and exhibited cavies for many years I have extensive experience in cavy care and husbandry. I currently have an active breeding program for pedigreed show animals but do not encourage backyard breeding for inexperienced owners. Although I don't encourage breeding for fun I'm always happy to answer any questions from an owner who is in sincere need of help. Pet owners wanting to breed should understand that even experienced breeders have litter losses. The mortality rate is high in cavies. The chance for losing both sow and pups is always present, even with experience. Although this is a site for experts to assist owners, there is no expert in any field who has all the answers. The wisest thing a good expert can know is their limitations. Not having an answer does not diminish one's ability or knowledge. It simply shows that we recognize our limitations and operate within them.


Raised and shown cavies for many years, having aquired my first cavies in the early 1970's as pets. My caviary currently handles 65 + animals in two different breeds and several varieties. Having been in the health care industry as a licensed nurse for 35 years I have hands on experience with care and needs in both humans and cavies. Member of American Rabbit Breeders Association and American Cavy Breeders Association.

Awarded Lifetime Membership in of one of the oldest cavy clubs in the United States, on whose Board I served as Sec/Treas for six years and currently serving as President. Also editor/publisher of the club's quarterly newsletter. We are strong supporters of our youth exhibitors, most of whom are 4H members who are working on cavy projects. Through these projects they become good responsible citizens. We deal with all aspects of showing, breeding, caring for and sharing experiences in the fancy. The cavy fancy is not a new one but in some areas is still relatively unknown. Our goal is to inspire interest in high quality, responsible breeding to improve the species, not just the reproduction of guinea pigs. Our job is to educate owners to help them make the right decisions and choices in the care of their cavies.

Graduate in nursing. Certified in emergency medicine.

©2017 All rights reserved.