Nutritional Secondary Hyperparathyroidism / Metabolic Bone Disease

Nutritional Secondary Hyperparathyroidism (NSHP), commonly referred to as “Metabolic Bone Disease”, is a common and serious health problem in pet reptiles. This disease causes the bones to become soft and brittle, easily bending and breaking. These fractures are referred to as pathologic fractures or fractures that occur during normal activity due to disease of the bone, not because of excessive trauma. In many cases, reptiles may have multiple fractures all over their body. Young growing reptiles may also develop swelling of the jaw and limbs, called fibrous osteodystrophy or “rubber jaw syndrome”. In severe cases, where the calcium in their body becomes dangerously low, reptiles develop muscle tremors, paralysis, and can lead to death.


NSHP occurs when a reptile is unable to absorb enough calcium into their bones. This can be due to a number of factors such as inadequate calcium in the diet, inappropriate calcium to phosphorus ratio (too little calcium with too much phosphorus), lack of exposure to UVB lighting, or inability to digest food properly due to low cage temperatures, dehydration, or parasites.

Most reptile diets are naturally very low in calcium but very high in phosphorus, resulting in an imbalance of calcium and phosphorus in the blood. This is why it’s important to utilize a good quality calcium supplement for your reptile. Click here for more information on providing supplements for your reptiles.

UVB lighting is very important. Exposure causes production of vitamin D3 within the skin tissues. Vitamin D3 is essential for absorption of calcium into the body from the reptile’s food. Some reptiles can get enough vitamin D3 from their diet, especially nocturnal reptiles, but most reptiles cannot. In nature, reptiles receive all the UVB they need from the sun. However, UVB light cannot penetrate glass, so placing your pet near a window will not help. Special light fluorescent and mercury vapor bulbs are available to provide this essential lighting to indoor reptiles. Click here for more information on UVB lighting for reptiles.



NSHP is diagnosed based on clinical exam findings, radiographs, and blood calcium levels. If the veterinarian diagnoses your reptile with this condition, treatment involves correcting diet and husbandry problems. Most cases will need prescription oral calcium supplementation with Calcium glubionate or injections of Calcium gluconate. Severe cases that don’t respond to calcium replacement therapy may need to have injections of the hormone Calcitriol injected. Broken bones require pain medication and possibly setting, splinting or surgery. Reptiles with this condition may be weak and require assist feeding with syringe diets.

A key factor in preventing this horrible disease is regular preventative health care. Annual veterinary examinations are recommended for all pets, even reptiles! An annual exam along with routine diagnostic testing at your veterinarian can help screen for and catch problems before they become life threatening. To schedule an appointment with one of our veterinarians for your pet click here.