Tortoises often refuse to eat when they are severely underweight. They also refuse food when they have been exposed to environmental trauma or dangerously low temperatures during hibernation, according to Tortoise Trust. Tortoises are extremely sensitive to dietary and environmental mismanagement.
Many tortoises suffer from post-hibernation anorexia. Post-hibernation anorexia is due to frost damage or insufficient weight when coming out of hibernation. Tortoises who are underweight require hydration. An owner should not force feed a tortoise, because it can result in death. Since tortoises have delicate renal systems, an owner needs to wait until the tortoise is rehydrated and urinating normally before he recommences feeding.
Once a tortoise starts eating again, a diet appropriate to its species is important. Cat or dog food causes potentially lethal changes in the blood urea levels of herbivorous tortoises. Complan and other artificial foods, on the other hand, often contain little fiber and can cause constipation in an already-ill tortoise. Tortoise Trust recommends providing liquidized green plant matter instead.
Environmental issues also trigger refusal of food. Hinge-back and box tortoises refuse to eat if their environment is overly dry. Mediterranean tortoises are prone to bacterial infections, which gives them runny noses and limits their appetite. Whenever a tortoise refuses to eat, a veterinarian visit is needed to diagnosis an underlying medical causes.