Reptiles and Metabolic Bone Disease

Ryan Navarro, DVM

Jan 2021

Reptiles are fascinating animals and can be a fun addition to welcome into your life, and with the proper care they can make quite wonderful companions.
However, improper husbandry can lead to serious disease manifestations with your scaly little friend. A very common disease seen with captive reptiles is a condition called Nutritional Secondary Parahyperthyroidism. In layman’s terms, this condition is known as metabolic bone disease (MBD).

leopard gecko diagram

It all starts with improper exposure to UVB radiation. In the wild, reptiles get this exposure from contact with sunlight. In captivity though, your reptile is totally dependent on your ability to provide it with exposure to UVB radiation with a proper UVB light. A brand new bulb should be presented to your veterinarian immediately to have it checked for proper radiation. Damage to the bulb incurred during the shipping process could render the bulb inadequate. Just because it’s a new bulb does not mean it’s a good bulb! Replace your UVB bulb once every 6 months and be sure to have it checked to ensure proper UVB radiation. UVB plays a critical role in the calcium metabolism of captive reptiles. Improper exposure can lead to life threatening metabolic disturbances and subsequent disease.

With proper UVB exposure, cholesterol accumulated in the skin can be converted to vitamin D3. Vitamin D3 then acts within the gastrointestinal tract, allowing for the intestines to absorb calcium obtained from the diet. Without proper UVB exposure, your reptile will not be able to synthesize vitamin D3. As such, your reptile can eat all the calcium it wants, but the intestines will not be able to absorb it and it will be all lost in the feces.

The body still needs calcium to accomplish its normal metabolic functions, and so if it’s not getting it from the diet, it will take it from the bones. If allowed to go without check, the body will deplete the calcium in the bones to the point where the bones become weak and prone to deformity and fracture. A sign of severe disease is known as rubber jaw, in which the bones of the jaw have been depleted of so much calcium it ends up becoming warped.

leopard gecko x ray

Calcium also plays a major role in the ability of smooth muscle to contract. The intestines are lined with smooth muscle, and so calcium depletion can result in conditions such as constipation and inappetence.

leopard gecko jawIt is also important to ensure your pet is getting proper nutrition. Poor diets lacking calcium can result in MBD as well.

Herbivorous, or plant eating species, need to be offered green leafy vegetables rich in calcium. Items such as romaine lettuce, dandelion greens, turnip greens, mustard greens,beet greens, kale, collards, bok choy, Swiss chard, escarole, spinach, and cilantro are all excellent choices to offer your pet. Additional items to provide a varied diet include squash, zucchini, sweet potato, broccoli, peas, beans, okra, and grated carrots.

Insectivorous species should be offered gut loaded insects. Crickets are best, but superworms, mealworms, wax worms, and locusts can be offered as well. Starve your insects for a period of about 8 hours, making sure they still have access to drinking water. You will likely lose some of the insects, but the idea is to make them ravenous. At this point, provide the insects with food items as discussed above. The insects will eat up the calcium rich vegetables and then in turn become rich in calcium themselves. Offer your pet the gut loaded insects in a separate enclosure for a period of 45 minutes to one hour. Any insects not consumed during this time should be taken away to prevent the risk of the prey attacking your pet.

leopard gecko diagramIf caught early, MBD can be corrected with appropriate changes in the husbandry of your pet and calcium supplementation. Some cases may need laxatives to help address issues with constipation. Some cases may need hospitalization and supportive care to correct. Advanced stages of disease carry a poor prognosis, and your veterinarian may recommend humane euthanasia.

If ever considering bringing a fun little reptile into your life, be sure to visit with your exotics veterinarian to discuss basic husbandry requirements for your new little friend. There is a lot of misinformation out there, but your vet will be able to provide you with evidence based recommendations regarding the optimal husbandry of your pet. We are here to help!

Call Us Text Us