As with most captive reptiles, most problematic medical conditions for which box turtles are presented to veterinarians result from malnutrition, either directly or indirectly. Box turtles are omnivorous. They will eat whole animals, such as meal worms, snails, slugs, earthworms and other invertebrates that may live in the humus and leaf litter in which box turtles normally hunt for food in their natural habitat. Box turtles also readily accept fruits, berries and certain vegetables.
Box turtles can be successfully raised by feeding a diet of whole animal substitutes, such as Reptile-Fare (Reliable Protein Products, Los Angeles, CA 90048), low-fat, soft dog food (Cycle 4, Gaines Foods, St. Anne, IL 60964), or semi-moist dog food (Gaines Burgers, Gaines Foods, St. Anne, IL 60964). Fruit (berries of all types, bananas, pears, peaches, papayas, guavas), vegetables (chopped, thawed, frozen mixed vegetables, squash, yams) and edible mushrooms should be provided as well. The fruits and vegetables provide additional vitamins, minerals and moisture, as well as necessary roughage.
Many hobbyists believe a ratio of 1/2 to 2/3 whole animals and/or whole animal substitutes to 1/3 to 1/2 fruit and vegetable matter offers the best results. Fruit-loving box turtles can be persuaded to eat a wider variety of foods by mixing soft dog food with pureed or chopped fruit. Other foods can be judiciously added to the aforementioned items, including cottage cheese, chopped hard-boiled or scrambled egg, grated cheese and yogurt.
A completely natural diet (one that a wild box turtle would select for itself) can never be exactly duplicated under conditions of captivity. For this reason, and because the exact nutritional requirements of box turtles are unknown, vitamin-mineral supplementation is advised. Powdered supplements intended for reptiles (Reptical and Vita-Life, Terra-Fauna Products, Mountain View, CA 94042; Reptovite, Verners Pet Products, Long Beach, CA 90807) should be sprinkled each day over food moist enough to ensure adherence of the product. We prefer the powdered vitamin-mineral-amino acid supplement, Nekton-Rep (Nekton Products, W. Germany) and believe it to be superior to the similar products listed above.
Environmental Temperature and Frequency of Feeding: Box turtles can be fed daily, though many hobbyists feed them every other day or 2-3 times weekly. They will not eat at low environmental temperatures and likewise cannot digest food well at low temperatures. Consistently warm environmental temperatures must be maintained, especially at night, for box turtles kept in colder climates, or for those not allowed to hibernate.