Guinea Pigs/guinea pigs


We have 3 guinea pigs and we don't know if there boys or girls so can you tell us how we know.

Sexing a baby boar
Sexing a baby boar  

Sexing a baby sow
Sexing a baby sow  
I hope you don't mind my changing this to a public answer. I get this question frequently so I'm hoping others will be able to learn as well.

It's of course easier if the pigs are grown, but most people have a very difficult time telling the sex when the pigs are very small. It's easier than it sounds and of course pictures are worth more than words.

These pictures are of babies less than a week old. But if you look carefully you can see there is a distinct difference. The trick is to hold the pig's body with one hand, then use your thumb and forefinger on the other hand to spread the genitalia apart.  

With a boar you will see a distinct line between the testicles. In babies the testes haven't yet dropped, but there is still a small pouch where they will be and you can see the line that separates the two testicles. Just above that line is a little 'dot', making the area look almost like the letter i. That dot is the penis.

In a sow the shape of the anatomy is different. In baby sows we refer to this as a 'Y'. You can see how the shape of the genitals on the sows are different. There is no separation. If you spread the area (called a vent) apart you will see the shiny tissues inside. As you spread it a bit that 'Y' shape becomes more obvious.

In grown pigs the boars are of course developed and the scrotum which houses the testicles is quite obvious. In a grown sow you can spread the vent apart easily and can see the shiny tissues inside the vent.

If you're still unsure you're seeing it correctly please send me a couple of pictures and I'll see if I can identify them easier for you.  Don't try to get your camera too close to the pig or it makes it blurry. It's easier if you take the picture from a foot away and I can zoom it up on my computer.

I hope this helps you out. After you've looked at a couple you'll find it's much easier than you think.

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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.

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