Irregular Shell GrowthIrregular show growth occurs from a combination of not enough sunlight, UV exposure, having vitamin D3 deficiency, not having enough calcium, or having a parasite problem causing the organs to malfunction internally. The temperature of the cage and the light cause the shell to grow properly.
If the shell has an odd shape to it then there is something at that point that is wrong with the diet or the conditions of the terrarium. A veterinarian should be consulted if there are any questions about the shell condition.
Proper Turtle Diet
Turtles require a variety of vitamins which include vitamins A, D, C along with all sorts of minerals such as calcium, magnesium, and so forth. A good diet of fresh foods such as whole preys such as grasshoppers, June bugs, slugs etc. as well as fresh vegetables and fruits provide the proper diet to keep the turtle in good health. Pieces of Kabul bone can be added to the terrarium so that the turtle chew on it and trim its beak in the process but at the same time will get the needed calcium it needs for its shell.
As a rule, box turtles need about as much vegetation as they do animal matter. They eat about as much vegetables or vegetation as the animal matter in equal proportions. It is important that the consistency of the food be relatively mushy because hard food contents can cause digestive problems. For example a carrot should be steamed rather than given whole. The turtle might not have enough sense to consume it properly and may injure its internal digestive systems.