Most tortoises are natural grazers, and in the wild will spend a large proportion of their day eating grass, plants, flowers and roots, depending on the species being kept. This diet is low in fat, sugar and protein, and high in fibre and calcium. Unsurprisingly, when offered some of our common vegetables and fruit, which are much higher in sugar and protein, tortoises get very excited! Unfortunately, these foods are not suitable to the way tortoises would naturally eat, and this has knock on consequences for their health. Ideally our pet tortoises should be fed as similarly to their wild counterparts as possible – think grasses, weeds, flower, leafy greens and herbs. High protein vegetables such as peas and beans, and high sugar options such as fruit and root vegetables, should generally be avoided or only given as a very rare treat. As well as plant matter, supplementing the daily diet with calcium (ideally alongside vitamin D3) and mineral supplement is a good way to make sure your tortoise is getting everything they need.
Young tortoises are especially at risk from nutritional imbalances are they grow. Slow even growth is best for long-term health, which can be obtained by feeding a correct and not overly rich diet. Even a few weeks on the incorrect diet can do lasting harm to a young tortoise. Adult tortoises are also not immune from the perils of a poor diet, which can lead to serious liver and kidney complications over time, as well as problems with bone and shell health.
Commercial ‘complete’ tortoise foods are also available. Many of these products can lead to problems, and should certainly not be the only source of nutrition for your tortoise. At most, a pelleted diet should be fed once or twice a week as a supplement, and should be soaked first.
Remember the diet does change with the species being kept. Savanah tortoises, such as the Sulcata, are grass grazers and need a large portion of their diet to be grass and hey. Some tortoises such as the Red-foot, yellow-foot, and box turtle, are omnivorous and will eat the odd insect or meat.
Although your tortoise may eat the commercial food happily, it is important to base your tortoise’s diet on what they need, rather than what they prefer. For example, many tortoises love tomatoes, cucumber and lettuce, but will get very ill on a diet based mainly around these ingredients. Like us, they have a tendency to prefer the foods that aren’t heathy for them!
Finally, all tortoises need fresh water every day. Although equipped to handle dry environments, reduced drinking puts strain on the kidneys, and is an unnecessary risk in a captive tortoise. Even when eating moist vegetables, your tortoise will not get all the water that they need from their food. Bathing your tortoise twice once or twice a week can help reduce any hydration deficit.
If you have any concerns about your tortoise’s diet, or notice any changes in their eating or drinking habits, get in touch with your local reptile-friendly vet as soon as possible.