Metabolic Bone Disease In Turtles [Causes, Prevention, Treatment]

If you ask me what is the deadliest turtle disease? I am sure MBD or metabolic bone disease will be in the top 3. Yes, this physical condition is dangerous for turtles. Yet, the keepers do not even know the bare minimum about this bone illness. Hence, I decided to talk about MBD in detail in this article.

Metabolic bone disease is a severe health condition affecting a turtle’s bones, shells, and muscles. This condition mainly results from a lack of calcium, vitamin D3, and UVB rays. Administering supplement shots and installing quality UV lights can cure the turtles. Additionally, providing a balanced diet is essential.

Keep reading for an insight.

Key Takeaways

• Turtles get splayed legs, shell deformity, and overgrown beaks due to metabolic bone diseases.
• Vets diagnose the condition by running X-rays, bone density, and blood tests.
• Supplement shots, medications, and a balanced diet can reverse the disease.
• If MBD goes untreated, the turtles can even die.

What Is Metabolic Bone Disease In Turtles?

Metabolic bone disease is more of an umbrella term. Conditions like osteoporosis, osteomalacia, and rickets are examples of this category.

However, nutritional metabolic disease is the most common in turtles or reptiles in general.

I wouldn’t call MBD a disease but a deformity. A turtle suffering from MBD experiences permanent bone/ shell damage or deformation.

For example, the bones might grow abnormally. The scutes will soften over time, and the legs can get splayed. Death due to metabolic bone disease is not uncommon in turtles.

One report claims that baby turtles with MBD can barely survive 1 year. Even if they live, their growth and immunity will surely be hampered. These turtles are also at the risk of experiencing paralysis at one point in their life.

As mentioned, MBD is a deadly condition in turtles. But the good thing is it can be cured. You can do the primary inspection and then take the pet to a vet for diagnosis. The sick turtle will get around with proper medication and lifestyle changes.

6 Causes Of MBD (Metabolic Bone Disease) In Turtles

I do not think you can blame only one reason for metabolic bone disease in turtles. Instead, several factors combined lead to this severe condition in the pets. The probable causes are,

1. Calcium Deficiency:

Turtles depend on calcium for their shell or bone growth. Lack of calcium in the system will thus result in underdeveloped or deformed posture. Besides, sometimes, turtles absorb calcium from the bones to maintain a healthy biological function. It weakens the limbs and joints and softens the shell and bones.

2. Insufficient Vitamin D3:

Turtles get vitamin D3 from 2 sources, food and the sunlight.

Though vitamin D3 does not promote bone growth directly, it has a definite link. For example, sufficient vitamin D3 in the system boosts calcium absorption, which influences healthy shell and bone growth. Therefore, it is obvious that lack of this vitamin will lead to weak skeleton build-up and deformity.

3. Mineral Imbalance:

Remember that now, every mineral is necessary for your turtles. A high percentage of phosphorus in the system inhibits calcium absorption. Therefore, the pets will always be at the risk of MBD.

4. No Access To UVB Rays:

Did I mention that the sunlight is a generous source of Vitamin D3? Of course, turtles do not receive this vitamin directly from the rays. However, UVB exposure from the sunlight promotes vitamin D3 generation in pets.

But what happens when turtles do not get enough UVB? Yes, they will suffer from metabolic bone disease.

Proper calcium and vitamin D levels are important for preventing MBD. A 2021 study investigated the bioaccumulation and effects of PFAS mixtures in wild freshwater turtles, finding certain PFAS compounds can interfere with calcium homeostasis and potentially increase MBD risk.

5. Low Temperature In The Enclosure:

Apparently, lower heat in the habitat can also lead to MBD. Experts suggest that the temperature drop will affect the pets’ digestion.

A defective digestive system causes nutritional imbalance, and thus, the turtles fall victim to MBD.

6. Secondary Disease:

Professionals claim that MBD can be a secondary effect of other illnesses. For example, intestine disease, liver failure, kidney disease, thyroid and parathyroid disorder, etc.

How Can You Spot MBD (Metabolic Bone Disease) In Your Pets? [Symptoms of mBD]

Unlike many other diseases, MBD is very visible. So do not worry about thinking that your turtle is suffering in silence. Absolutely not. You will definitely witness physical symptoms, especially in bones, shells, and muscles.

Common signs of metabolic bone diseases in turtles are,

• Scute softening
• Shell deformity
• Jaw deformation
• Weak limbs
• Splayed legs
• Swollen limbs
• Paralysis
• Flat shell
• Abnormal beak growth
• Cloaca prolapses
• Constipation
• Loss of appetite
• Lethargy, etc. 

These are not all. The situation can get worse. Turtles face trouble walking because of the jerky gait or bowing of limbs. In most cases, they just drag their bodies forward.

Sometimes, turtle shells grow too big, and deformities add more weight to them.

The entire thing can backfire on the pet’s health. For instance, the turtle has to endure immense pain as the weight will squeeze the internal organs and nerves.

The shell feels too tight in many scenarios, and the pets can not even retract inside properly. Now remember, shells are there to protect these reptiles from any potential predators. When turtles can not withdraw from their shells, it will make them frustrated.

The deformed shell seems to affect the spine of your turtles. It results in paralysis.

Furthermore, the soft scutes can be proven dangerous, too. For example, a simple scratch can lead to shell rot and infection. However, do not just pass your judgment by observing the shell only. Baby turtles have soft shells that are not fully developed. Some turtles, like softshell turtles, have squishy shells from birth.

A 2023 study characterized the osteodensitometry and tomographic findings in four captive giant South American turtles (Podocnemis expansa) with MBD. The study described bone density measurements and bony changes seen in the turtles, providing insights into diagnosing and managing MBD.

How To Diagnose Metabolic Bone Disease In Turtles?

Of course, you can tell whether a turtle is suffering from MBD with the symptoms I have mentioned earlier. But apparently, these are not enough to start the treatment. Hence, the vets recommend proper tests to diagnose the disease.

Reliable tests that help diagnose MBD are,

• X-ray
• Bone density test
• Blood test, etc.

Vets also ask for the sick turtle’s medical history, habitat setup, and lifestyle for accurate diagnosis.

What Are The Available Treatments for Metabolic Bone Disease?

Though the MBD sounds horrible and complex, the treatment procedure is not. In fact, you can cure your pet with only a few changes in its enclosure and lifestyle. A typical treatment for the sick turtle looks like this,

• The vet will diagnose the pet first.
• He will then prescribe supplement shots or injections if the condition is severe.
• In many cases, the turtles are hospitalized for better treatment.
• The reptile can stop eating due to MBD. Vets might force-feed the pet in such scenarios.

Besides veterinary treatment, a home remedy is also necessary. Here is what you have to do,

• Discover the root of the illness first. Solving the issue will reverse the condition in no time.
• Make sure the turtles are getting enough exposure to UVB rays.
• The meals must include sufficient vitamin D3 and calcium.
• Set the habitat temperature to a comfortable zone.

Can You Prevent MBD (Metabolic Bone Disease) in Your Turtles?

By now, you have realized one thing for sure. A poor diet and habitat mismanagement lead to metabolic bone disease in turtles. It means that the condition can be easily prevented. The tips I blindly follow to keep my turtles safe are,

• All my turtles have easy access to the UVB rays. While the open basking spot is enough for my outdoor pond turtles, the indoor ones rely on UVB bulbs. I have installed the best quality light for my turtles.
• I follow a strict diet for my pets. The babies eat every day, and the adult ones are fine with a thrice-a-week meal schedule. I usually add calcium supplements to the food thrice a week. Calcium in any form (cuttlebone, powder, or block) is okay for turtles.
• Some owners offer their turtles multivitamins, too, once a week. I do not use any other supplement other than calcium.
• It is crucial to offer the turtles a healthy and balanced meal. The bowl should include vegetables, plants, leaves, and protein. Check the mineral percentage of each item. The calcium-phosphorus ratio should be 2:1.
• Low temperatures can disrupt the biological function of turtles. Therefore, you must be careful in this matter. Turtles want a basking temperature of 85F to 95F. Besides, there has to be a temperature gradient from cool to warm (from 75F to 85F) for the pets.

case studies that illustrate the impact of MBD on turtles

Case Study 1: Giant South American Turtles:

A study on four captive giant South American turtles (Podocnemis expansa) with MBD highlighted the use of computed tomography (CT) scans for diagnosis. The scans revealed significant demineralization and structural changes in the turtles’ bones, illustrating the severity of MBD in captive turtles.

This case underscores the importance of early diagnosis and potential treatment options for MBD in turtles.

Case Study 2: Success Stories in Rehabilitation:

Various case studies and success stories have shown the potential for rehabilitation in turtles with MBD. These cases involve treatments that combine proper nutrition, UVB light therapy, and calcium supplementation, leading to significant improvements in the turtles’ health. This includes cases handled by veterinarians, rehabbers, rescue organizations, and dedicated turtle owners.

Before You Go…

Metabolic bone disease is just one of the many potential health conditions for turtles. The pets can suffer from shell rot, mouth infections, and even eye diseases. I have talked about 38 health conditions in turtles and their probable treatments here:

38 Box Turtle Diseases & How To Treat Them