When choosing a guinea pig for a pet, look for an animal that appears healthy, plump, and alert. The animal may initially be fearful or skittish but should, in a short time, respond positively to gentle stroking. Check over the animal carefully. The eyes should be bright and clean, not crusty or lusterless. The nose, eyes, ears, and anus should be clear and free of any discharge or discoloration. The teeth should be clean and unstained and the long incisors in the upper jaw should overlap and just touch the bottom pair. Check the feet to be sure they are well-formed and move easily. The feet should be uninjured and without flakes, red spots, and scars.

Also, look at the housing for the guinea pigs you are considering. The cage or enclosure should be clean, with very little odor. The animals should not be too crowded, as this can lead to stress and may lessen resistance to disease. In many cases, guinea pigs will be kept in mixed (male and female) groups. Because female guinea pigs can become pregnant as young as 2 months of age, this often means that even a fairly young female guinea pig can be pregnant at the time of purchase.

Ask the seller about a prepurchase veterinary check. A responsible dealer will either allow a check by an outside veterinarian or will agree to accept back a diseased or pregnant animal that has been promptly examined by a veterinarian. If possible, have your new guinea pig examined by a veterinarian before you take it home or as soon as possible thereafter.

Last full review/revision July 2011 by Katherine E. Quesenberry, DVM, MPH, DABVP (Avian); Kenneth R. Boschert, DVM, DACLAM