It can be extremely difficult to determine the sex of a very young guinea pig. You can wait until the guinea pig is 2-3 weeks old to sex it, at which time it is easier to determine the sex [3] X Research source . However, since males must be separated from their mothers and sisters at 3 weeks old, it is crucial to sex them by this time. Otherwise, they can impregnate their mothers and sisters. Don’t worry about handling young guinea pigs. Their mother will not reject them and early handling can help make them less afraid of humans. [4] X Research source
Don’t worry about wearing gloves. Very few human diseases can be given to guinea pigs and they do little to stop diseases from spreading from pig to pig.
Cavies dislike being on their backs for a long period of time. Try to do the examination quickly and efficiently. You may want to ask someone to help you hold the cavy while you conduct the examination to speed up the process. Give your guinea pig a treat while doing this. It will make them easier to work with and less scared.
Once you have distinguished between the cavy’s anus and the cavy’s genitals, you can look at the distance between the cavy’s anus and the cavy’s genitals. Female guinea pigs have a shorter amount of space between their vulva and their anus. Often, the vulva sits right above the anus in female cavies. Male guinea pigs have a larger amount of space between their penis and their anus, about 2-3cm of space between the penis and the anus.
Male cavies have a genital opening that is shaped like a small circular dot with a penis raised above the level of the surrounding skin. Male guinea pigs have a bulge to their genital and anal areas. The bulge appears due to the presence of the guinea pig’s testicles, which are just under the skin along the anus and the penis. You should also check if there is a donut shape around the cavy’s anus, as this is where a male cavy’s testicles will sit.
You can also use your finger to gently press and rub just over the genital area. If you feel a “ridge” just over the genital area, you are feeling the inner part of cavy’s shaft. This is a clear sign the cavy is male. While checking for the penis, look and feel for testicles on either side of the penis to confirm that the pig is a male. The testicles are rather large relative to the size of the pig’s body.
You may also want to bring your guinea pig to the vet if your guinea pig appears distressed during the examination or reacts poorly to the exam. It may be difficult to get an accurate reading of the cavy’s sex if the cavy is stressed out or moving around a lot during the home exam.
