One of the most important aspects of tortoise care is proper diet; therefore, please follow these guidelines to ensure the health and longevity of your tortoise. For a complete list of foods to provide and to avoid for a captive tortoise, click here. Tortoises will accept many foods that are not good for them and may appear completely healthy for years on a poor diet. In reality, poor diets, such as those that are rich in sugars (including fruits), protein, or animal fats will impair organ function and may result in the eventual death of your tortoise. Please do not make the mistake of viewing a tortoise as if it were a child or typical pet. They are reptiles with specific diet needs, outlined below.
The desert tortoise is completely herbivorous (plant eating), and in the wild, it browses on a wide variety of plants. Likewise, in captivity, the best diet is one that provides a variety of foods to meet its nutritional needs. Ideally, a captive tortoise should be allowed to graze on grasses, leafy plants, and flowers that you have established in the tortoise’s habitat. For example, grass can contribute a significant portion to your tortoise’s healthy diet if you establish a patch large enough for your tortoise to browse when it is hungry (at least 6’ x 6’ in size). Other plants that you can establish in your yard that provide a varied diet include native grasses, dichondra, filaree (heronbill), spurge, dandelion, hibiscus, wild grape, mulberry, and wildflowers such as globemallow. Your tortoise will enjoy the leaves, stems, and flowers of these plants. You can purchase native plant seeds at the Arizona Native Plant Society website: http://aznps.org/html/az_plant_sources.html or by inquiring about native plants at a local nursery. If you establish plants in your backyard for your tortoise to graze on, they must be planted inside the enclosure in sufficient quantity to allow daily grazing. Please exercise caution to insure that captive tortoises cannot consume toxic plants such as oleander, chinaberry trees, tree tobacco and toadstools.
Commercial produce is, in general, less nutritious than native plants for tortoises due to higher water and lower fiber content. However, you can provide produce as a supplemental food source or on a daily basis if you are unable to establish plants for browsing. Dark greens rich in minerals and vitamins such as collard, kale, mustard greens, beet greens, turnip greens, cilantro, spinach, and parsley, can be offered as a short-term alternative or as a supplement to grasses. When dark greens and acceptable produce are offered, they should be clean, fresh, and chopped into pieces small enough for the tortoise to eat. Lettuce provides little nutrition and should be avoided entirely. Do not feed your tortoise dog or cat food, monkey chow, or any food that contains more than 15% protein. These will cause liver and kidney damage, as well as deformed shell growth.
Fruits, including cactus fruits, should only be offered as a special treat. Once a month or so you can give your tortoise a small piece of fruit such as a strawberry, a ¼ of a peeled banana, or a ¼ slice of peeled cantaloupe. Fruit has too much sugar and water to be fed in large amounts, and should only be fed in moderation (no more than 10% of the diet). Sugar and starch disrupt digestion by changing the type of bacteria that live in the tortoise’s hindgut. Do not feed tortoises frozen vegetables or sodium-rich foods including canned vegetables, dairy products, breads, and celery.
Supplemental foods should be served on a dish or feeding platform to prevent ingestion of gravel or sand, which can cause gastrointestinal irritation or impaction.
Make sure that water is available in the enclosure at all times. Keep the water dish in the same place so the tortoise knows where to find it. Your tortoise will get a lot of its water from its food, so you may not see it drink frequently. However, tortoises enjoy soaking occasionally, and so the water dish should be just a few inches deep, and wide enough for the tortoise to sit in.