Bearded Dragon Metabolic Bone Disease (MBD)

Metabolic Bone Disease in Bearded Dragons is common, can be fatal and completely avoidable. Learn how to recognise the signs and prevent it before it happens

Bearded Dragon With Mbd
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Metabolic Bone Disease In Bearded Dragons

In simple terms, Metabolic Bone Disease (MBD) is a complicated way of saying that your bearded dragon’s bones are becoming too soft due to them not having enough calcium content in them. It’s calcium in bones that make them strong and hard. So, if there’s not enough calcium in their bones then the bearded dragon bones become soft and brittle. The can bend or break and this of course leads to major deformities and pain for your bearded dragon.

Metabolic Bone Disease in bearded dragons is caused by the potential failure to receive a number of key components that are required for calcium absorption and metabolism. If any of these components are in short supply or missing, your bearded dragon will develop metabolic bone disease.

  • Calcium
  • Vitamin D
  • Ultraviolet Light – specifically UV-B (though UV-A is necessary too, but for different reasons)

Calcium is obviously required since it’s a chemical element and cannot be made or synthesized at all, except perhaps by a nuclear reaction inside a star. It is a very important electrolyte (ie, it has an electrical charge) and is essential for proper nervous system control and heart control due to the regulation of the electrical impulses that control muscle actions.

Vitamin D is required because with Vitamin D your bearded dragon cannot absorb any calcium from its diet. Vitamin D plays a number of important roles in metabolism of calcium, starting with the ability to absorb calcium into the bloodstream from the gut. Without Vitamin D this initial (and any subsequent) steps can’t happen. The National Institutes of Health have a web page explaining in great detail the different mechanisms that Vitamin D exerts on the body relating to healthy calcium levels and therefore bone density and nervous system function. It’s heavy going and it refers only to humans, but the principles are largely the same for bearded dragons.

Ultraviolet Light (B Subtype) is a requirement listed above because although Bearded Dragons can have dietary supplemented Vitamin D, the best way for them to get the Vitamin D is to create it for them for themselves through the UVB interacting with their skin to produce it.

Therefore, insufficient calcium and Vitamin D is a significant problem for your bearded dragon. Fortunately, there’s plenty you can do to make sure your bearded dragon gets enough.

How To Avoid Bearded Dragon Metabolic Bone Disease

Given that MBD in bearded dragons (and other reptiles) is so insiduous and dangerous – and irreversible if it gets too advanced – it makes sense to try to avoid it in the first place. Fortunately, with the right husbandry, metabolic bone disease is completely avoidable.

Calcium Rich Diet

Since no animal (or plant for that matter) can synthesize Calcium, it has to be absorbed in their diet. Thus, the diet must consist of calcium rich foods. Fortunately, many of the things we recommend to feed our bearded dragons are fairly high in calcium – which is why they tend to be recommended. Have a look at What Vegetables Can Bearded Dragons Eat for more information about which vegetables have plenty of calcium. Don’t guess. Not all vegetables have all the calcium they contain available for absorption. We’re looking at you Spinach. Masses of calcium, but lots of it unable to be metabolised.

Calcium Supplements

Since some of the foodstuffs we give our bearded dragons isn’t that great in calcium, and since they need so much of it, there exists calcium supplements to help boost the amount of calcium a bearded dragon will get from their diet.

Supplements are NOT a substitute for a good, natural balanced diet. They will help boost the available calcium though.

Beware supplements that also contain Vitamin D3. It might seem that since Bearded Dragons can synthesize Vitamin D3 through their skin when it comes into contact with UV-B then we should supplement with D3 as well. Whilst this is true, VitD3 supplementation is also, no substitute for proper UV-B lighting in their tank.

This is because some evidence suggests that the bearded dragon skin will reduce the Vitamin D3 it generates when their is enough in their body – whereas supplements short circuit this process. Too much vitamin D3 means too much Calcium absorption and that calcium has to be stored in the bones. If the bones are full, the calcium become excess calcium and will form painful spurs and possibly eventually seize joints. This is known as Hypervitaminosis D and can be just as bad as MBD, so it’s a delicate balance.

PROPER UV-B Lighting

This cannot be overstated. Your bearded dragon requires PROPER UV-B lighting from a fluorescent strip light mounted in the vivarium. Not only that, but they require a very high amount of UV-B light, so any old UV-B lamp is not suitable.

The following lamps are NOT SUITABLE;

  • LED Strip Lights
  • Coil UV-B Lamps
  • Fluorescent Strip Lamps that are less than 10% strength.

You need a fluorescent strip lamp that is rated at 10-12% strength that is as long as at least three-quarters of the length of your vivarium. If your vivarium is 4 feet long therefore, your UV-B lamp must be at least 3 feet long.

Bearded Dragon Heating and Lighting gives more information on which UV-B lamps to choose, including the differences between those that are mounted inside the tank versus those that are mounted outside. The lifespan of the lamp is not infinite and must be taken into account, meaning it should be replaced every 9 months. This too is discussed in the article about heating and lighting.

Spending Time Outside

Many experts agree that taking your bearded dragon outside when the sun is out can provide as much Vitamin D for your dragon in 15 minutes as they can produce for the entire rest of the day. Obviously this depends where you are in the world and what time of year it is. But we do recommend, if it’s warm enough, bearded dragon owners to take their bearded dragons on supervised visits outside.

Bear in mind, UV-B cannot penetrate glass very well – so there is nothing to be gained by allowing your bearded dragon to sit at the window looking out.

Having The Correct Vivarium Temperature

Having the right temperature is also vital for the proper metabolism of your bearded dragon’s food. If the temperature is too low in the vivarium then your bearded dragon won’t be able to properly digest their food. This can lead to impaction as well as metabolic bone disease.

Check your temperatures are adequate by checking the data in Bearded Dragon Heating And Lighting.

How To Help Bearded Dragons With MBD

Metabolic Bone Disease in bearded dragons is not curable. The only thing you can do is to prevent it getting any worse. In severe cases, unfortunately, the kindest thing to do is to have a discussion with your vet about euthanasia. In even mild cases a chat with the vet about the best way forward is definitely recommended, as they may need calcium booster injections which can only be obtained via a vet.

Obviously, to prevent the MBD getting worse, you’ll need to make sure they have a calcium rich diet, with supplements. They can be supplemented with Vitamin D3 as well. And it’s essential that they have the correct UVB lighting – a 10 or 12% Desert rated UVB strip light ( T5 or T8 ) that is three quarters of the length of your vivarium. This UVB strip light must be changed at least every 9 months – and possibly every 6 if your beardie has MBD.

Because the bones of a bearded dragon with MBD are soft, you may need to make some changes to their habitat too. Ledges and places up high present a falls risk and with bones that aren’t strong enough, there’s a risk of fractures and other internal injuries. Beardies with soft bones will also likely have deformities that make it much harder for them to climb and balance. Removing these might be a good idea.

A bearded dragon with MBD deformities is going to find it hard to move quickly enough to catch food, so you’re probably going to need to get used to feeding them by hand. If they’re still able to catch food, but are clumsy with it and miss a lot of the time, switch to a hard, non-loose substrate if they’re on something like sand or wood shavings (which we don’t recommend at any time anyway).

One of our rescues has some physical deformities probably from MBD and she’s an extremely clumsy feeder. She doesn’t quite need feeding by hand, but we definitely couldn’t keep her on a loose substrate as she’d eat more of that than she would insects.

To summarise, ways you can help your bearded dragon with MBD

  • Make sure they’re getting enough calcium and Vitamin D so they don’t get worse.
  • Make sure their UVB lamp is the correct type, strength and length. And change it every 6 – 9 months as they do deteriorate.
  • Remove high ledges, hammocks or other falls risks to minimize risk of broken bones or internal injuries
  • Remove loose-substrates and use something like tiles if they’re struggling to catch prey
  • Be prepared to hand feed (NOT syringe feed unless advised by a vet)

Bearded Dragon Health Complications Due To Metabolic Bone Disease

The most obvious health complication of severe metabolic bone disease is that the bearded dragon’s bones become soft and brittle, leading them to be easily deformed or break completely. An example of this is shown in the video below which is provided in memory of Export – a bearded dragon who was rescued by a member of our Facebook group but sadly was too late and passed away from his illness in 2020.

Calcium’s role in the homeostasis of the body is important (homestasis basically means everything being kept in balance and running smoothly) because it plays such a big part in the electrical systems of the heart and nervous system as well as providing the main building block for skeletal system.

The animal body is a finely balanced machine. The bones of an animal act, to some extent, as a resevoir for calcium. A very narrow range of calcium in the blood is required for proper functioning of the animal. Any excess calcium is stored in the bones. And if there’s not enough calcium in the blood for proper operation of the nervous system, muscles and heart then the animal’s body will ‘raid’ some of the calcium from the bones.

Most people think that once the bones are made they are inert, no longer alive and don’t change. This, however, is not true. They are constantly being added to, repaired, broken down and modified. So a constant source of calcium is always needed.

So, now we know that the bearded dragon’s body will automatically regulate the calcium in the blood by using the bones as a store and release system we can begin to understand what happens if there’s constantly not enough calcium in the blood system. The ‘store’ part of the process never happens, and since calcium is lost through everyday metabolism, the only part that happens is the release process.

Thus the bones lose calcium and become brittle and/or soft. Eventually the lose so much calcium they break or deform.

We’ve also mentioned that calcium plays an enormous role in the nervous and cardiac systems. Calcium helps to regulate the electrical impulses in the brain and nerves that serve the body. The breaking down of calcium from the bones is a relatively slow process. But the calcium in the blood is required constantly for nervous system control, so if it starts to drop, then the nervous system is impacted.

This is why MBD causes tremors, seizures and/or paralysis as well as bone issues. Ultimately, due to it’s role in the electrical system of the heart, a lack of calcium will cause a lethal heart arrhythmia and your bearded dragon will die. To be fair, by the time they get to this stage they’re likely to be severely deformed anyway.

Is Metabolic Bone Disease Curable?

This depends on the stage your bearded dragon is at in the process. If they have become deformed due to the calcium deficiency in their bones then it’s unlikely that they’ll return to their original structure. Your bearded dragon will be permanently deformed from now on.

However, solving the problems that cause Metabolic Bone Disease in bearded dragons will prevent their deformities getting any worse and will reduce the tremors, seizures or paralysis that they’re experiencing.

Advanced Metabolic Bone Disease is going to need regular veterinary appointments to monitor blood calcium levels, possibly with calcium and Vitamin D injections to get everything back on track. It’s best to avoid MBD in the first place.

Prevent Metabolic Bone Disease

If you love your bearded dragon, and we’re sure you do or you wouldn’t be reading this, it’s super important to prevent MBD. We see lots of bearded dragons in terrible shape whose owners could have avoided harming their bearded dragons just by looking up (or asking) what is needed to keep one.

If you’re concerned that your bearded dragon is not behaving normally, or has the shakes/tremors or is paralysed, the first questions you’ll be asked is how are your temperatures and UV lights. This should now be obvious as to why. Temperatures and lights play such a vital role in keeping MBD away, and MBD will make an active dragon lethargic or twitchy or even paralysed.

We hope this article helps you to prevent Bearded Dragon Metabolic Bone Disease. If you have any questions, please don’t hesitate to leave a comment and ask. We’ll do our best to help.