Quality hay is a staple for rabbits, guinea pigs, and chinchillas.

This topic is less controversial than the dog/cat discussion. But it’s no less important. Inappropriate husbandry, especially nutrition, is the major contributor to illness in small pet mammals. So, here’s what we currently believe about diet in these species.

Rabbits. Nutritionally, they’re just little horses (without the hooves). They are obligate herbivores that rely heavily on long fibers in their diet to stimulate proper digestion. They obtain very little nutrition per pound of this high-fiber diet, so they must eat a very large volume compared to their body weight. Pelleted “rabbit food,” although an acceptable component of their diet, is very concentrated and should play a very minor role. Here’s the best formula for your typical adult rabbit: unlimited timothy hay kept elevated in a hay feeder, 1/4-1/3 cup of quality pellets (Oxbow makes a good one), and a large handful of mixed greens (collard greens, parsley, cilantro, mint, carrots tops, etc) per day. For a complete list of bunny greens, visit the House Rabbit Society website.

Guinea Pigs. Like humans, guinea pigs cannot synthesize Vitamin C and must obtain it from their diets. If adequate Vitamin C is not supplied, they can suffer from scurvy, which leads to swollen joints, appetite loss, and bleeding. Otherwise, guinea pigs are a lot like rabbits, who need long grass fibers for proper digestion. They should be given unlimited timothy hay or orchard grass, a small amount of pellets (the kind that is supplemented with Vitamin C), and ¼ cup of dark greens to provide additional vitamin C (kale, collard greens, chard). Guinea pig pellets should be purchased in small quantities, as the Vitamin C is volatile and the food “expires” 60-90 days after it’s made. It is possible to purchase Vitamin C supplements for guinea pigs; but this is not necessarily advisable, as it is possible to give too much.

Chinchillas. Not much is known about the feeding habits of wild chinchillas, except that they feed on grasses. Commercial chinchilla pelleted diets are available and can be given in small amounts, along with ample quality timothy hay or orchard grass. Like rabbits and guinea pigs, the long fibers of the grasses are necessary for digestion, so pellets alone are not sufficient. Occasional treats of apple, hazelnuts, raisins, or branches (elm, maple, ash) can be offered.

Rats and mice. They can be omnivores or vegetarians. But, like children, they will sort though a bowl of mixed food to pick out only the tastiest sweet/fat morsels. So, they do best on a “lab block” diet supplemented with fruit and vegetable treats. Quality lab blocks, like those made by Harlan Taklad, will provide all necessary nutrition and can be purchased in either regular or vegetarian formulas. Oxbow Regal Rat is another great choice. Regal Rat is available in pet stores but Teklad is sold mainly through rat and mouse clubs. Your internet search for “Buy Harlan Teklad lab blocks” will take you to several clubs that sell these foods. While lab blocks might not look like fun for your little rodents, the superior nutrition might just add months to their lives. You can supplement with fresh vegetables and the occasional fruit. Some rats and mice also like timothy hay or hay cubes.

Hamsters. Little is known about the feeding habits of wild hamsters, except that they are omnivorous and will eat fruits, seeds, insects, and plant materials. In captivity, they fare well with pelleted diets like Oxbow Healthy Handfuls or the types of lab blocks described for rats and mice. These can be supplemented with low-sugar, low-fat treats like fortified breakfast cereals, uncooked pasta, or whole grain bread.

Hedgehogs. Relatively little is known about the natural feeding habits of African hedgehogs. The current recommendation is for high protein (30-50%), moderate fat (10-20%) and some fiber. I recommend 2 tsp insectivore diet (four reputable brands are Mazuri, Reliable Protein Products, Walkabout Farms, and ZuPreem) and 1 tsp finely chopped vegetables (green beans, peas, carrots, broccoli, spinach, kale, lettuces – all sprinkled with a little vitamin/mineral mix). Add in 6 small gut-loaded mealworms or silkworms or 1-2 crickets for fiber. Avoid wax worms, as they are too high in fat.

Sugar gliders. Unfortunately, much of what is circulating about sugar glider nutrition is incorrect, with the effect that these pets live only about 4 years in captivity versus 10-14 years in the wild. Contrary to a common misperception, sugar gliders are insectivores rather than fruit eaters. The proper diet for a pet sugar glider is 50% insectivore diet (see “Hedgehogs” above for suitable brands) and 50% Leadbeater’s mixture (using a blender, combine 150ml warm water, 150ml honey, one hard-boiled egg, 25gm high protein baby cereal, and 1 tsp dry vitamin/mineral supplement). Occasional treats can include gut-loaded crickets, silkworms, or small amounts of fruits and veggies sprinkled with vitamin supplement.

Ferrets. These are the meat eaters in the group. Their ideal diet is 30-35% animal protein, 15-20% fat, <4% fiber, and minimal carbohydrates. So, cat and dog foods are too high in carbs and fiber to be good choices for ferrets. In the US, we feed primarily pelleted ferret diets, compared to Europe, where they typically feed whole prey, like mice or pinkies. Many manufacturers make suitable ferret diets, including Marshall, Purina/Mazuri, and Kaytee. While occasional treats are fine, fruits, vegetables, dairy, and sweets should be strictly limited, as they can cause diarrhea.

Gerbils. Although most “gerbil” food is actually packaged for both gerbils and hamsters, gerbils actually need less fat in their diets that their hamster friends. That said, the most sensible gerbil diet is still pelleted hamster/gerbil food (like Oxbow Healthy Handfuls) supplemented with timothy hay and a small amount of chopped veggies.

Small furry animals can be great fun and very rewarding pets. It’s important, though, to provide good husbandry, starting with a nutritious diet. Fortunately, most of these species have good commercial foods available and can enjoy the occasional fun treat.

A note about commercial “mixes” for rodents: Many companies make rodent mixes for rats and mice and for hamsters and gerbils. These “party mixes” are made from rolled grains, nuts and seeds, and dried vegetables and pastas. Because the animal can choose to eat the high-fat nuts and seeds while leaving the “healthy” grains, these are not ideal diets. If you adopt a rodent pet that has been raised on “party mix,” it might take you a few weeks to convert him to a pelleted diet; but it’s best for his health that you do so.