Diseases Affecting the Shell

Retained scutes: "Dysecdysis" is the term to describe the condition in which an old scute is retained and not shed properly. This condition is often associated with poor husbandry, and may occur if the turtle has not been able to dry off or bask sufficiently to lose its old scutes. Retained scutes often become infected. A turtle with dysecdysis should be examined by a veterinarian.

Metabolic bone disease: A turtle with an inadequate calcium or Vitamin D intake, inadequate exposure to ultraviolet light, or disease of the liver, kidneys, or parathyroid glands may develop metabolic bone disease. This causes softening and malformation of the bones. The shells of turtles with metabolic bone disease are often deformed, with the rear area of the carapace pulled downward, and the marginal scutes pulled upward. Tortoises with metabolic bone disease may develop pyramid-shaped scutes. Metabolic bone disease can be fatal; turtles suspected of having this disease should be examined by a veterinarian. Husbandry and diet changes may be able to correct the calcium imbalance, but deformities are generally permanent.

Renal failure and sloughing of scutes: Although rare, renal failure in a turtle has been reported to cause a turtle to slough his scutes. Kidneys help to maintain the proper calcium and phosphorous levels in the blood. If the kidneys fail, the phosphorous level in the blood increases. The turtle's body attempts to compensate by moving calcium from the bones into the blood stream. The bones in the shell, then, can become soft.

Ulcers: Ulcers of the shell may be superficial or deep, and may be termed "shell rot." Ulcers are generally a result of poor husbandry. Turtles with ulcerative shell lesions should be examined and treated by a veterinarian, as the ulcers may become infected and penetrate through the shell. The shell will need to be cleaned daily, and dead tissue removed. Topical and/or injectable antibiotics are required in the case of bacterial infections. Deep ulcers may need to be repaired through surgery and the application of acrylic or fiberglass material. In a disease called "septicemic cutaneous ulcerative disease," or SCUD, ulcers may be seen on both the shell and legs. This condition is often associated with the bacteria, Citrobacter freundii.

Injuries: Injuries due to trauma or burns can cause pain, can lead to infections, and may cause misshapen scutes as they heal. Although the shell has a remarkable ability to repair itself, any turtle with an injury to the shell should be examined by a veterinarian immediately. Fatal infections can occur.

Other causes of deformed scutes: Scutes may also be deformed in size or shape due to genetics or improper egg incubation.

The shell of a turtle is an amazing adaption which has allowed turtles to exist for millennia. The proper diet, husbandry, and care are vital to maintain a healthy shell.