Male guinea pigs can be identified by the shaft of a penis or testicles. Determine the sex of a guinea pig with tips from a veterinarian in this free video on guinea pigs and pet care.
My name is Endre Sos and I will tell you how to determine the sex of a guinea pig. This guinea pig is a little bit active but otherwise guinea pigs reach sexual maturity very soon so even if you buy a very young female it can be pregnant so therefore it s crucially important to determine the sex of your animal. If you gently elevate the animal and just lean it against your chest. You have to stand in front of a mirror. This animal doesn't know me so it is a little bit anxious and so to do it gently but firmly use the rump area and you are using and just looking for a Y shaped area. It is here you can see within my fingers and in females this Y shaped area if you open it there is a small slit so she is a female in my hand. In young males you will see the shaft of the penis and in older males it is often very obvious to see the big testicles which are around in this area. Seeing the testicles can be tricky because there is no scrotum so the animal can withdraw its testicles to the abdominal cavity so it is not always visible but usually in bigger animals it is also quite obvious.