Do Rabbits and Guinea Pigs Get Along?

When I first adopted my rabbit Nimbus, I noticed that he had several significant bite marks on him. I asked the rescue group where these marks came from, and the worker explained that Nimbus had lived with an aggressive guinea pig, who had fought with him frequently. Nimbus's original owner surrendered him to end the conflicts. Guinea pigs and rabbits don't always get along, but some do. The ability of rabbits and guinea pigs to get along depends largely on the temperament of each individual animal.

Animals are Individuals.

The common question, "Do rabbits and guinea pigs get along?" is as fluid and answerless as the question, "Do cats and dogs get along?" or "Do dogs and people get along?" Animals, like human beings, are individuals and can't always be lumped into assumptions based on their species. Some rabbits are incredibly docile, while others are intensely aggressive. Likewise, many guinea pigs are sweet and social, but others bite, scratch and otherwise engage in territorial and dominant behavior.

Guinea Pigs and Rabbits are Social Animals.

Both guinea pigs and rabbits naturally live in social groups, and they do best when interacting with other animals. Due to their similarity in temperament and social structure, guinea pigs and rabbits may get along very well in a captive environment, helping to keep each other calm and occupied. However, rabbits and guinea pigs also both engage in somewhat aggressive behaviors to establish dominance and determine territory. The tendency toward both bonding and aggression can be at once both helpful and problematic.

Rabbits and Guinea Pigs Need Extra Territory.

A standard-sized cage isn't big enough to be a full-time habitat for even one animal-- and especially not two. Some guinea pig and rabbit owners make the horrible mistake of keeping both animals penned up inside one tiny cage. This will inevitably lead to territorial disputes between the animals, and they may hurt or kill each other in an attempt to claim enough space for both creatures. To keep guinea pigs and rabbits peacefully, maintain separate cages for both animals, and supervise their interactions when they are both loose in the house.

Remember Each Animal's Own Requirements. 
Although it won't hurt your bunny to occasionally nibble guinea pig food, and won't hurt your guinea pig to chow down on bunny food, it's important to remember and maintain the individual needs of both animals. Separate food, bedding, shelter, and roaming space are critical for enabling each animal to thrive. Remember that those broad "small animal foods" usually provide inadequate nutrition and aren't appropriate for feeding both cats and guinea pigs.

Neuter your Males.

It's a good idea to spay and neuter your pet no matter what, but this is particularly true when it comes to cohabitating rabbits and guinea pigs. Male rabbits mark their territory with intense skunky-smelling spray, as do male guinea pigs. When two in-tact males share the same home, they can quickly begin engaging in a spray-war, which will stink up your house and ruin your carpet. For the sake of your own sanity and hygeine, get your male animals snipped at your local vet's office.