Rabbits and cavies make good companions FALSE Rabbits and guinea pigs must never be mixed. A single kick from a rabbit, whether accidental or not, can seriously injure or even kill a cavy. Even a dwarf rabbit can cause serious harm to a guinea pig. Rabbits and cavies also have different nutritional requirements. Guineas cannot manufacture their own Vitamin C and need plain pellets containing this vitamin as well as regular fresh veggies. Rabbits do not need the extra vitamins in their dry food as they can create their own Vitmain C. By feeding just rabbit pellets, the cavy misses out on essential nutrients. By only feeding pellets designed for cavies, the rabbit misses out on the nutrients required to maintain their health. It is virtually impossible to keep rabbits and cavies together because of this reason alone.
Rabbits also carry certain organisms which can be passed onto the guinea pig, potentially causing life-threatening symptoms. While the organisms may not be so harmful to the rabbit, it can prove fatal to a different species of animal.
For more detailed information on reasons not to mix rabbits and cavies, visit
http://www.cavycages.com/rabbits.htm