Keeping guinea pigs with rabbits is not recommended for several reasons:
Different dietary needs - guineapigs require a diet higher in vitamin C than rabbits. Rabbits require a diet higher in vitamin D than guineapigs.
Different language - Guinea pigs and rabbits communicate with each other in very different ways, they're both better off with a friend that talks the same language.
Injuries - Rabbits have very powerful backlegs and can injure a smaller guineapig friend by mistake even if the do get on most of the time.
Rabbits and guinea pigs are herding animals, so even if they dislike each other their instincts will tell them to seek company when nervous or lonely. So they are forced together. They cannot commicate their wants or needs to one another, so if the rabbit or gp is in a mood the other doesn't know and could get (fatally) hurt. Also it's not always pysical damage, it could also be psylogical, just acting aggressive or too hyper will terrify a pig.
Plus I have heard of a rabbit killing a gp even though they have been living together for over a year.
The disease that rabbits have that can kill guinea pigs is called Bordetella bronchiseptica. Rabbits should be kept with rabbits and gps with gps. Even if you do have hiding places for the pig, what's to stop the rabbit from picking it up and throwing it or squeezing into it, you'd be amazed the small spaces they can squeeze into.
If you need some more convincing read these!
rabbits
http://petsinfoworld.blogspot.com/20...o-not-mix.html
Rabbits With Guineas
Rabbits N'Rodents | Got Rabbits, Hamsters, Guinea pigs, gerbils?
This quote I think rounds it up real nicely
Quote:
Social Life. Have you ever watched two rabbits together? They like to snuggle and groom each other constantly. Guinea pigs, on the other hand, do not groom each other on a regular basis. Nor are they habitual cuddlers. Instead, they like to maintain their own personal space and don’t often like to share. In this kind of environment, a rabbit could become very lonely and a guinea pig might start feeling harassed. Keep in mind, then, that rabbits and guinea pigs are quite different animals, one of them desiring a close, affectionate bonded pair, the other sharing a more limited interaction with a herd.
I personally wouldn't take the risk, it only needs one accident and the animals are much, much happier with their own speices, I know my rabbits would miss the attention of the other rabbit if they lived with a pig instead.