Understanding Metabolic Bone Disease (MBD) in Reptiles
Metabolic Bone Disease (MBD) is a common yet serious condition affecting captive reptiles, particularly those that require UVB lighting and a source of dietary calcium. MBD is caused by calcium deficiency, improper calcium-to-phosphorus ratios, and a lack of vitamin D3, which is crucial for calcium absorption. If left untreated, MBD can lead to severe skeletal deformities, fractures, and even death.
Causes of MBD in Reptiles
MBD occurs due to one or a combination of the following factors:
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Lack of UVB Exposure: Many reptiles, such as bearded dragons, iguanas, and turtles, require UVB light to synthesize vitamin D3, which is essential for calcium absorption. Without sufficient UVB, their bodies cannot properly use calcium.
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Calcium Deficiency: Inadequate dietary calcium and/or improper UVB lighting strength leads to weak bones, muscle tremors, and deformities.
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Poor Calcium-to-Phosphorus Ratio: A diet high in phosphorus but low in calcium (such as feeding too many insects without dusting with calcium supplementation) can interfere with calcium absorption.
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Lack of Vitamin D3: Without vitamin D3 (which can be synthesized through UVB exposure or supplemented in the diet), calcium cannot be effectively metabolized.
Symptoms of MBD
MBD presents with a range of symptoms that worsen over time if left untreated. Common signs include:
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Soft or Deformed Bones: Swollen, bent, or misshapen limbs, spine, or jaw ("rubber jaw").
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Fractures and Weak Bones: Spontaneous fractures or difficulty supporting body weight.
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Tremors and Muscle Twitching: Uncontrolled movements, tremors, or difficulty moving.
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Lethargy and Weakness: Reduced energy, trouble climbing, or dragging limbs.
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Loss of Appetite: Decreased interest in food, leading to weight loss.
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Paralysis: Severe cases may result in partial or full paralysis.
If you suspect your reptile may be showing signs of MBD, it is important to get them into a reptile knowledgeable vet as soon as possible.
To find a reptile vet near you, check out the Association of Reptile and Amphibian Veterinarians Vet Finder tool
For even more information, check out our article on How to Prevent and Treat Metabolic Bone Disease (MBD)
