Rabbits and Guinea-pigs have different dietry requirements
Rabbits require coccidiastats in their diet
Guinea-pigs need vitamin C in their diet.
Welfare
should be united at a young age
It is not generally a good idea to house rabbits and guinea-pigs together
Rabbits may cause injury to guinea-pigs as guinea-pigs are much smaller
Best to pair females as males tend to fight
Rabbits may bully guinea-pigs and become competitive for resources
Rabbits can become over amourous towards the guinea-pig
When providing an animal such as a rabbit with accomodation you must consider the animals natural behaviour and reproduce as much of it as possible
Rabbits should be able to stand on their hind legs with erect ears and be able to hop three spaces, turn and hop back without coming into contact with the walls or roof of accomodation
Examples of this include; climbing, jumping, digging, knawing