Dr. John Harkness, laboratory animal veterinarian at Mississippi State University's College of Veterinary Medicine, said packaged pet foods do not always meet pet rodents' dietary needs. Some of these feeds include seed mixtures, vitamin and mineral additives, hay cubes, food pellets, salt blocks, chewable wood and treats. Labeling is a serious problem with some pet foods, especially for guinea pigs, Harkness said.
Many food labels claim to be for all rodents, but diet requirements actually vary greatly.
Recommending diet supplements often can lead to nutritional imbalances. Many owners supplement pet diets with fruit, vegetables, hay or other treats. These should not replace more than 10 percent of the regular diet. Older animals can have 25 percent of their diet in supplements, as the additional fiber can limit obesity and other problems. A recommended rodent diet is a reasonably fresh pellet containing essential nutrients and at least 16 percent crude protein.