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Sungazer Lizard With Metabolic Bone Disease

Our lizard seems to have lost the ability to move his back legs and tail. What's wrong?

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We have owned an adult dwarf sungazer for more than three years. We have had no problems until last week. Our dwarf sungazer seems to have lost the ability to move his back legs and tail. I have not seen him move them for over a week. His mobility is not that good. His front legs seem fine.

When offered food and water, he drinks and eats. Although very listless at first, he seems to have picked up over the last few days and appears a little happier. In fact, with him being very shy, I was surprised he fed whilst being handled. We did not force him to eat. We took him to our local vet, but he was unable to assist us. The nearest vet who would see a reptile is more than a two-hour drive away, and we do not want to risk the stress of the journey.


I have a hunch that it may be a stroke, but obviously this is a guess. Any advice would be greatly received. We don’t want him to suffer and would not want to prolong his life if he was unhappy.

It would have been helpful if you could have provided me with some husbandry information regarding the temperature range of the habitat and the type of lighting that you used. Sungazers are from the Republic of South Africa, and they acquired their name by the method in which they bask in the sun. Natural full-spectrum lighting is very important for the health of all diurnal lizards, and herps in general. If you have not been providing natural sunlight (not filtered through glass or plastic, which removes the necessary ultraviolet portion of the spectrum) or full-spectrum artificial lighting for your lizard, I suspect this is the root of the problem.

Certainly, I will be unable to diagnose your lizard’s problem for you, but I would be happy to give you my thoughts on what is going on with your dwarf sungazer. Do you gut-load the insects before feeding your lizard? Do you dust the insects with a calcium supplement? Are you offering high-calcium greens and limited fruits (some sungazers will eat some vegetation)? Fruits tend to be higher in phosphorus and lower in calcium, in most cases.

My suspicion is that your lizard is suffering from nutritional secondary hyperparathyroidism, also called nutritional metabolic bone disease (NMBD). This occurs when a lizard is not exposed to the UVB ultraviolet wavelengths of light, and/or if the lizard is not ingesting or utilizing calcium properly. Please have a look through the archived questions and answers, as I have addressed this condition on several occasions. NMBD is most common in rapidly growing green iguanas, but can be seen in any herp species (although snakes seem rather resistant to succumbing to this condition). Basically, herps require UVB light to convert nutrients to active vitamin D3, which is necessary for the proper uptake and utilization of calcium by the body. Early signs may be changes in ambulation; for example, a lizard may not be able to rise and walk lifted up off the ground, or the tail may become flaccid, or as has occurred with your lizard, there may be problems with weakness or paralysis of the hind legs and tail.

Some herps may survive for years without proper lighting and temperature range, however, with time, most will succumb to nutritional problems from deficiencies and imbalances. When a herp is suffering from NMBD, it will usually have very high levels of phosphorus in its system and low levels of calcium in the bloodstream. However, for a body to survive, it must maintain the blood calcium level within a very tight range, so it will usually pull calcium out of the tissues, with very deleterious effects to the bone structure, which will weaken over time. This weakening can result in spontaneous bone fractures from normal movements or bones may actually implode from the weight of the chest and abdomen weighing down the spinal column. This results in weakness or paralysis of the hind end usually.


I don’t know where you live, but I am assuming it is not the United States (your whilst gives you away). If you do live in the U.S., then you can ask your local vet if he or she will help you out by requesting a consultation with an experienced herp vet. Most of the large veterinary diagnostic laboratories offer consultations with specialists and experienced herp vets, and this is usually a free service. However, I am not aware if this service is offered by veterinary diagnostic labs in other countries, but if it is, this may be your best bet.

If your local vet doesn’t mind asking for help from an experienced herp vet, then, you can ask him to set up a consult. You can download this information, plus the other information on NMBD, for your vet to review prior to the consult. There are specific therapies for NMBD, and diagnostics for confirming that this is what your sungazer has. Radiographs (X-rays) often show a decreased density of the bones, and may show fractures. Blood tests may show increased phosphorus levels, and low to low-normal blood calcium levels, along with an increased alkaline phosphatase values. The consultant can explain how to take diagnostic radiographs, where to draw blood from and what treatment should be instituted, based on test results.

Should you put your lizard through all of the testing and diagnostics? That I cannot tell you without evaluating your sungazer and the test results. With many cases of NMBD, it may be possible to stop the damage, and reverse it, but many lizards may be left with long-term irreversible damage from fractures and bone abnormalities. It is possible to administer hormones (calcitonin salmon) via injection, which will put the calcium back into bone and other tissues, as well as administering injectable and oral calcium supplements, vitamin supplements and other support care. But only time will tell how much function your lizard may regain. Often problems related to pelvic fractures and constipation will be irreversible, and this may end up being the deciding factor in whether or not it is possible to save a lizard with NMBD.

At this point, it will not be enough for you to just try to administer a calcium supplement orally. You really do need to find a vet who can help you with your lizard’s problem. I hope this information will prove helpful to you. And for my other readers, when asking me a question, please try to provide me with information regarding diet, supplements and habitat (and if you cannot tell me your pet’s habitat temperature ranges, then you must purchase at least two good quality hygrometer/thermometers, one for the basking area and another for the cooler area of the habitat). I also need to know what kind of lighting that you are providing for your pet, and if you are using artificial lighting (with ultraviolet spectrum), how often you are replacing the bulb. If you can provide me with this information, I can better advise you regarding your problem.


Margaret A. Wissman, DVM, DABVP has been an avian/exotic/herp animal veterinarian since 1981. She is a regular contributor to REPTILES magazine.

Need a Herp Vet?
If you are looking for a herp-knowledgeable veterinarian in your area, a good place to start is by checking the list of members on the Association of Reptilian and Amphibian Veterinarian (ARAV) web site at www.arav.com. Look for DVMs who appear to maintain actual veterinary offices that you could contact.