RABBITS AND GUINEA PIGS They both need hay and plenty of it. It is a food that they must consume in large quantities and at will. It is absolutely essential for their health. The same goes for vegetables, such as carrots. Yet many people provide nothing but animal feed for their rabbits and guinea pigs, when in fact, they should only have a little. If your pet refuses hay, it might simply be because they don’t like it! But don’t worry… you don’t have to trek to the country to find a kind they like! Your vet can provide you with an excellent quality product.