How to Determine the Sex of a Guinea Pig

Guinea pigs can multiply rapidly, even at a young age. It is essential to determine a guinea pig's gender to eliminate the chance of an unwanted litter. Even very young sows may be carrying babies when purchased from a pet store. By learning to tell the sex of guinea pigs, you make an informed choice when bringing one into your home.

Difficulty: Easy

Instructions

1. Calm the guinea pig. Hold it close to your body, speaking in a soothing tone while stroking its fur.

2. Hold the piggy gently but firmly. Place one hand under its rump. Put your other hand on its chest, under the front legs.

3. Stand close to a mirror. Pull the guinea pig upward, its back against your chest, exposing its full underside.

4. Use your rump-holding hand to spread the guinea pig's back legs and closely examine the genital area.

5. Look for a Y-shaped opening. Females have a smooth area of skin in the crook of the "Y." Males have a penis head that looks like a small, round "button" of skin. In older males, testicles are often evident just under the "Y."

6. Tap the genital area gently if you are still uncertain. In females, the "Y" will open more fully. In males, the penile shaft will slowly expose itself.

Tips & Warnings

• A boar's penis is usually tucked away under the skin. The shape of it is often visible if you look carefully.
• If you are still in doubt, get a second opinion. Always know a guinea pig's gender before bringing it into your home.

Resources

• View photos to help determine a guinea pig's sex.