good information! you should request to make a sticky thread like we have done in the rabbit forum. this way everyone can have input and give good links etc.

on the rabbit and guinea bit, I would also add that rabbits may hump gunieas and brake there pelvises as they cant take the weight or the aggressiveness. also they speak different languages and cant understand each other, but will huddle for warmth. also they have massive differences in dietary requirements, by feeding your guinea pig often cheaper rabbit food they are missing out on the essential vitamin C that they cannot naturally produce like rabbits can, this can cause a variety of health problems including scurvy.