Health Topics

Guinea Pigs

(By P. Alderson DVM)

Guinea pigs are native to South America and are related to the chinchilla, hedgehog and porcupine. They are also known as cavies. There are many varieties, which include English, Abyssinian, and Peruvian. They readily interbreed, so mix breeds are possible. If handled regularly and gently they rarely bite or scratch and make excellent pets.


Guinea pigs are not athletic and cannot jump or climb. Thus, they don't need a cage that is entirely enclosed. A tub or basin with high smooth sides is sufficient for housing. The flooring should be solid. DO NOT house a guinea pig on slatted floors as their feet will get caught and they will break their legs. They are relatively clumsy, so climbing up the sides of wire cages should be discouraged. They should not have wire exercise wheels.

Guinea pigs produce large amounts of very odorous urine. The concentration of ammonia can build quickly, causing pneumonia. Be sure to clean the cage very regularly and allow adequate ventilation.

If you would like to provide an exercise wheel, make sure it is smooth plastic that will not allow its feet to get caught. Exercising your guinea pig around the house is acceptable. Be careful to "guinea pig proof" your house, looking for dangers such as electrical wires, stairs, and tight spaces.

The temperature should not be too hot, as guinea pigs can over heat readily. Keep the environmental temperature around 65 - 75 degrees F. Do not allow access to direct sunlight, and keep them inside on hot days.


Guinea pigs have an absolute requirement for vitamin C. They can not make their own vitamin C as other animals can, so MUST be provided with extra dietary vitamin C to prevent scurvy. Vitamin C in commercial guinea pig diets rapidly decays when opened and is not generally adequate. You can provide vitamin C supplements in the water or break apart a chewable human vitamin C tablet (1/4 of a 100mg tablet). If you provide vitamin C in the water, you MUST change the water every 24 hours. Foods high in vitamin C include guava, papaya, parsley, broccoli and kale. A guinea pig requires a minimum of 20 - 30 mg of vitamin C daily. Stress or illness will increase these requirements.

Guinea pigs tend to gain too much weight if place on a diet of pellets. Hay should be provided for fibre, filler, and chewing. Pellets should be offered, but in small quantities (one to two tablespoons daily). Fresh water should be provided at all times. Guinea pigs will defecate in a water dish, so a sipper bottle is preferred.


Handle guinea pigs frequently to prevent shyness and aggression. Handle them gently and support the hind end to prevent spinal injury. They can be easily excited and can dart away quickly should they become frightened. Guinea pigs can also "stampede" or run wildly in circles if scared.


Guinea pigs are creatures of habit and like things to remain the same. A change in food, environment, and even feeders or bedding can be very stressful. Occasionally they will stop eating if a change has occurred, which can lead to illness or death. If you must make a change, if at all possible make the change as gradual as possible.

They are messy housekeepers, so frequent cleaning is necessary.

Females will, generally, get along with other females. Be careful if introducing a male however, as females can fight with males, and males generally will not accept other males. They can be housed alone.

Do not breed a female for the first time if she is over a year of age. She is too old for her first litter and you will risk a problem pregnancy or a broken pelvis. Gestation is long, around 63 - 72 days (as per a dog or cat) and the litters tend to be small (around 1 - 4 young per litter). The young are generally weaned by 21 days of age.

Veterinary Care

Guinea pigs can live up to 8 years if well cared for. Yearly checkups should be a routine part of their care. They do not require vaccines. However, they can have dental problems that must be addressed. Dental malocclusion, or abnormal tooth growth, can prevent a guinea pig from eating and cause starvation and death. Signs of this include slobbering or drooling, weight loss, or the inability to chew food properly. This needs immediate veterinary attention as they can easily starve to death.

Guinea pigs are also routinely spayed and neutered for pregnancy prevention and general good health.

Other common ailments include skin disease, urinary infections, pneumonia, constipation or rectal impaction, diarrhea, scurvy, rickets, and epilepsy. Lice and mites are common. Care should be taken if using cat and dog flea shampoos. Seek veterinary advice prior to bathing your guinea pig in a flea shampoo.