Reproductive Problems In Rabbits And Guinea Pigs

By Dr Joanna De Klerk

As rabbits and guinea pigs are becoming increasingly popular as pets, it’s important to understand some of the most common problems of our furry little friends.

Most rabbit and guinea pig owners are unaware that reproduction issues can be very common. In fact, a study in Europe of 1000 guinea pigs, showed that reproductive diseases were the third most common problem, after dental and skin problems.

Rabbit and Guinea Pig Reproduction

Small furries go through puberty at a very young age. Rabbits enter this stage in their life at four to five months old, and guinea pigs at only two months old. Once they’ve gone through puberty, the problems can start. It’s a common misconception that you’ll only have reproductive problems if you breed with your guinea pigs or rabbits, but in fact, there are many problems they can suffer from, even when they are not breeding animals.

It’s wise to get your rabbits and guinea pigs neutered or spayed, not only to prevent breeding, but also to prevent reproductive health ailments. Females are more likely to have reproductive problems than males. However, neutering males reduces unwanted mating and aggression, so it’s still worth taking them to have the surgery.

Most veterinary practices will be able to offer neuter and spay surgeries for your rabbit or guinea pig. Unlike dogs and cats, it might require a hospital stay overnight to monitor them closely, as anaesthetics can slow down the guts of small furries, and therefore it’s important to ensure they are eating and defaecating properly before they go home again. Surgery can be performed at 4-6 months of age for rabbits and 5-6 months of age for guinea pigs.

Guinea Pig Reproductive Diseases

Ovarian cysts

Female guinea pigs are prone to developing ovarian cysts. By one-year-old, 5% of guinea pigs will have them, increasing to 22% at two years old, and a whopping 70% by six years old.

There are several different types of cysts, but they are broadly categorised into two groups; functional and non-functional. Functional cysts secrete hormones, which can lead to hair loss on flanks and the back, and increased pigmentation of the nipples. However, non-functional cysts are far more common. These do not secrete hormones, but grow very large in size, resulting in abdominal distension and inappetence. This can potentially become life-threatening.

Some cysts can be treated with hCG hormone injections to decrease their size, but surgery to remove the reproductive organs and including the cysts immediately resolves the problem.


If your guinea pig falls pregnant, it’s not always happiness and joy when it comes to birth. Guinea pigs are very prone to a birth complication called dystocia. This is when it is impossible for the mother to push the baby out.

The main reason for this is that after six months of age, if they haven’t had a litter before, the pelvic bones become fused, resulting in a small pelvic canal and the inability for babies to pass through it. In addition to this, when the baby is too big, which is very common if the litter size is small, it also contributes to the problem. Other reasons for dystocia include twists in the uterus, exhaustion and obesity (another common problem of many pet guinea pigs).

Your vet can give your guinea pig calcium injections to improve the strength of her contractions, however in many cases and emergency caesarean surgery will need to be performed since it is physically impossible for a baby to come through the pelvis.

Rabbit Reproductive Diseases

Uterine cancer

Cancer of the uterus in female rabbits is very common. Approximately 50-75% of unspayed female rabbits older than three years develop uterine cancer. Out of those, almost half of them have metastatic, terminal cancer which has spread to the lungs. This type of cancer is called uterine adenocarcinoma. 

The most common symptoms of uterine cancer are weight loss and blood-stained vulval discharge.

Uterine tumours can and should be removed by surgery, but because of the high rate of spread, it will not always cure the condition. Once it has spread to the lungs, there is nothing that can be done, and keeping your rabbit comfortable is the most important thing.


Pseudopregnancy, also called phantom pregnancy, is when the body thinks it’s pregnant, but it actually isn’t. It’s a debilitating condition, that will make your rabbit feel unwell and very hormonal. It often leads to aggression, pulling out fur, and mammary gland development.

It can be caused by many things, including simply unfortunate luck, but the most common of which is a functional cyst.

Due to the development of the mammary glands, milk is often produced, but since there is a lack of babies to drink the milk, your rabbit is likely to end up with mastitis; an infection of the mammary glands. This is a painful condition and requires veterinary treatment, but you can improve the comfort of your rabbit by placing warm (not hot) heat packs on the mammary glands.

Rabbit Syphilis

Rabbit syphilis is caused by a bacterium called Treponema cuniculi. It sticks to the skin around the face, nose and genitals, where it replicates and causes scabs, blisters and ulcers. It can be spread through sexual transmission, close contact and babies suckling from their mother.

Even though it is highly contagious, and can be present on a rabbit for years without showing any signs, it is easy to treat. Your vet can give antibiotic injections, which usually clears the problem completely. Of course, eating with blisters around the mouth is not comfortable, so you might need to syringe feed and nurse your rabbit back to health while the blisters are healing.

Take Home Message

Rabbits and guinea pigs are popular pets, and if you have recently added one to your household, it’s important to consider getting them neutered or spayed. This will prevent many reproductive problems and help them live a healthy, long life.

Further Reading