Metabolic Bone Disease and Your Pet Iguana

Metabolic bone disease, otherwise known as MBD or fibrous osteodystrophy, is a common disease that affects many pet lizards including iguanas, geckos and monitors. A nutritional deficit disease, MBD occurs when owners are unable to maintain the proper environment and diet required by a reptile species. Metabolic bone disease is also commonly referred to as calcium deficiency, as it deals with the reptile's inability to properly absorb calcium.

Why Is Calcium So Important to My Iguana?

As small children, our parents always tell us to drink milk because the calcium will help make strong bones and teeth. The same is true with iguanas and other reptiles - they need strong teeth and bones in order to survive in the wild, but calcium also helps reptiles with important things like muscle contraction and blood clotting too. When they aren't absorbing sufficient amounts of calcium, iguanas and other reptiles can become weak, lethargic and may even die.

How Reptiles Absorb Calcium

In the wild, reptiles spend a large amount of their time stretched out and soaking up the sun. This isn't just because it feels good to lounge about in the warm sunshine, but because it helps them raise their body temperatures and assists them in the digestive process. The UVB radiation, that comes from the sun's rays, helps to convert cholesterol into vitamin D. The vitamin D then moves to the liver, then on to the kidneys and is finally released into the intestinal tract where it helps the lizard absorb calcium through the lining of the intestinal wall. If any part of this process is disrupted, the reptile is unable to properly absorb the calcium that he needs.

How MBD Occurs

Metabolic bone disease is a condition that is limited to captive reptiles and is usually due to poor husbandry or dietary mismanagement. Here are the most common occurrences for calcium deficiency in iguanas and other reptiles.

Improper Enclosures - In order to keep your pet iguana healthy and happy, you need to mimic his natural habitat as much as possible. Iguanas are arboreal reptiles, meaning that they spend most of their time up in trees. Needless to say, if your iguana can't climb and hide in amongst the foliage in his cage, chances are he won't be very happy. Over time, improperly housed iguanas can become stressed and stop eating, leading to MBD and other serious conditions. Regardless of what kind of reptile you have, it's essential to his well-being that you do your utmost best to mimic his natural habitat.

In addition to making your reptile's enclosure look like his natural environment, you also want to ensure that you maintain sanitary conditions, keeping it clean of feces, dust, molds and other unhealthy things. It's also important to maintain a proper level of humidity in the enclosure as well - be sure to research your particular species and the proper levels of humidity that they require. Failure to do so can stress your lizard and may cause them to stop eating. Also important to note is that you should also offer water according to your lizard's particular needs - since many lizards use water bowls for bathing and defecating, it's important to know if your lizard needs to drink from a bowl or, like a chameleon, prefers to drink water droplets from the leaves in his enclosure.

Lighting - As discussed earlier, iguanas and other reptiles require direct sunlight in order to properly digest their food. It cannot be stressed enough that placing your iguana in an aquarium and then setting it beside a sunny window will NOT cut it (not only will this not give your iguana the proper amount of UVB rays, but it also runs the dangerous risk of overheating his tank. Never ever do this.

Because few people are able to give their reptiles the amount of sunlight they need on a daily basis, special UVB lighting has been developed for use in reptile enclosures. By following the normal photoperiods, or amount of daylight that your reptile species should have, UVB bulbs are an excellent way of keeping your pet iguana healthy. Just be sure the light you are purchasing is a UVB light - basking or heat bulbs, halogen bulbs or full spectrum bulbs are not the same as UVB bulbs. They may be less expensive, but they will not help your pet reptile digest food.

Diet - Needless to say, diet is an important part of keeping healthy pet iguanas. In the wild, reptiles eat different things and it's important to mimic this, just as you try to mimic the environment in their enclosures. While there are commercial foods available on the market, these are usually expensive to buy and don't provide reptiles with a good variety. Before you get in the habit of buying the same thing, every week, ask yourself if you'd really enjoy eating the same meal, every day, with no changes. Some iguanas can become bored when fed the same diet and will stop eating - offer a variety of healthy fruits and vegetables for your iguana and you'll find he looks forward to dinner time.

Calcium supplements are also an important thing to add to your captive reptile's diet. By lightly dusting their food with a calcium supplement, you can be sure that they are getting a sufficient amount on a regular basis.

Signs Your Iguana May Have MBD

There are many signs that your iguana may have metabolic bone disease, but the most commonly-seen symptoms are a crooked back, soft nose, lack of toe use or twitching toes, swelling of the limbs or jaw, or not closing the mouth all the way. A gentle palpitation of the jaw can also be done, to see if it feels soft, but be careful not to squeeze too hard or you may hurt your iguana.

Another, more drastic symptom of MBD is frequent bone breaks. As the reptile's bones are depleted of calcium, they become more and more brittle, resulting in broken bones. If your pet iguana suffers from any of these symptoms, there is a good chance he may have metabolic bone disease.

What Can I Do?

Fortunately, MBD is reversible, particularly if it's caught early on. In many cases, you can reverse the effects of MBD simply by improving your reptile's environment and diet - by providing him with proper exposure to UVB rays and improving his diet and natural surroundings, most iguanas and other reptiles will rally around and begin to properly absorb the needed calcium once again. In severe cases, calcium injections may be administered by a veterinarian that is specialized in the care of reptiles and other exotic pets.

Sources:

Personal experience

http://www.baskingspot.com/ - Information on dietary findings and recipes for iguana diets

http://www.triciaswaterdragon.com/mbd.htm - Information on Metabolic Bone Disease