How old are your bunny and guinea pig Steph?
Can I mention something, and my intention isn't to freak you out, but I think it definitely will!
I work at a shelter, and I rehome the rabbits and guinea pigs. I NEVER rehome rabbits and guinea pigs together. They are also not housed together. Here's an explanation from a forum why not to house rabbits and guinea pigs together:
It is never ok to keep them together under any circumstances im afraid....
Here are the reasons.
1. The dominant behavior of the rabbit often means the guinea pig(s) get injured and to put it bluntly they do not speak the same language and nipping ect is a rabbit method of communication.
2 They both require a different diet....get it right for the rabbit and it will be wrong for the guinea pig and visa versa.....potentially very serious for both.
3 A large number of rabbits carry a bacteria commonly called Bordatella which is nothing much more than a sniffle for the rabbit but is pathenogenic to the guinea pig and frequently the only sign is a dead guinea pig in the morning. It follows that 99.9% of such dead guinea pigs just get disposed of and no autopsy or subsequent investigation takes place so the incidence of this is probably much higher than is thought.
It may never happen of course, the bordatella thing, but that's why we say not to risk it.
It's best to have rabbits with rabbits and guinea pigs with guinea pigs.
If you're concerned at all, or wish to get a vet check, can I suggest the best rabbit clinic in the world for bunnies and guinea pigs? Melbourne Rabbit Clinic. It's in Ferntree Gully.
www.melbournerabbitclinic.com
I'm going there tomorrow, I'll ask them if they've seen much of it.