How Do You Determine the Sex of a Guinea Pig?

If you’re wanting to introduce a new guinea pig into your home then it’s crucial to be confident in their sex, especially if you are introducing them to a group with unneutered piggies. While most guinea pig breeders and pet shops sex them before selling or displaying, it never hurts to have a look yourself.

Guinea pigs standing side by side

How to Tell if a Guinea Pig is a Boy or a Girl

There is only one physical way to determine if a guinea pig is male or female, and that is by taking a look at their genitals. Guinea pigs are not sexually dimorphic, meaning males and females don’t have individual physical characteristics based on their sex. Both females and males will look almost identical.

Depending on where you acquired your piggy from, whether that be a pet shop or guinea pig breeder will determine if they have been properly sexed or not. A chain pet shop most likely will be selling male and female piggies, but it’s possible they haven’t been sexed correctly. This typically isn’t done with the purpose of misleading a buyer, but that those sexing a guinea pig simply are not trained on how.

If you have bought your furry friend from a guinea pig breeder, then they are much more likely to give you an accurate answer on the sex. Sexing pups can be a little tricky due to their small size, so there is still a small chance the breeder may have got it wrong. In any situation, it wouldn’t hurt to have a look yourself just to double check.

How to Sex a Guinea Pig

The process of sexing a guinea pig isn’t complicated at all, it just takes a little handling. If you believe to have a male guinea pig, then double-checking their sex may be super straightforward. For a male guinea pig, you can lift them up and see if you can see their testicles. Just as with most mammals, they are visible externally. If you aren’t able to see them, then you may need to take a closer look at their genitals.

The method of checking is relatively simple, though may be unpleasant for piggies who are not a fan of being held. Once you have got them out of their enclosure and into your arms, you’ll want to gently flip them onto their backs. When they’re in position, and you have some decent lightning to see, you can get sexing.

Male and female guinea pigs’ genitalia look distinctively different. A female guinea pig will have a noticeable ‘Y’ shape. A male guinea pig will have more of an ‘i’ shape, where the penis represents the dot on the ‘I’. If you are a little unsure of what you’re looking at, then you can apply slight pressure just above the shape. In a male, this will make the dot stick out a little further confirming it’s a male.

Can Male and Female Guinea Pigs Live Together?

Of course! Male guinea pig and female guinea pig pairings are some of the most ideal dynamics to have for a guinea pig group. When thinking about pairing male and female guinea pigs together, it’s important to note there should only ever be one male per group. Having multiple males can lead to them fighting one another for dominance. They can get quite rough, and no one wants to see their male guinea pigs get hurt.

There are several ways to house male and female guinea pigs together. One option is to have them as a pair, just one male and female. This is a great option if you’re not able to keep more than two guinea pigs. They will still be able to carry out natural behaviours and the mixed sex group will feel much more familiar to them.

The second option is to have a single male in a group of multiple females. This group structure will feel most natural to them, as guinea pig herds are run by a dominant male, and on average there are about 3 – 10 guinea pigs in a herd.

Though, it’s crucial to ensure any male in a group is neutered. Mixing unneutered males and females is practically guaranteed to equal in many guinea pig pups.

A mother and her pups

Male Guinea Pig Behaviour

Male guinea pigs are known to be pretty confident. They are usually much more inquisitive than females and are much more likely to approach you when you’re around. Due to their boldness, male guinea pigs are often easier to bond with, and you can form strong relationships quite quickly. This leads them to being easier to handle, which makes grooming and vet visits straightforward.

However, while male guinea pigs are often friendlier with humans, they can be a little more aggressive to other guinea pigs, especially other unfamiliar males. They typically will fight other males for dominance, particularly if there are female guinea pigs around. 

Female Guinea Pig Behaviour

In comparison to males, female guinea pigs are quite reserved when it comes to human interaction. They tend to want to hide more often and are less likely to approach anyone unfamiliar. This can make bonding, grooming or any type of handling a little more challenging, as they will be more resistant to interacting with you. That doesn’t mean bonding is impossible though! Females are fully capable of bonding with you, they just require a little more patience.

On the other hand, female guinea pigs are much more confident with other guinea pigs. They are less likely to show aggression to other guinea pigs as they are much less territorial.