Metabolic Bone Disease

Metabolic Bone Disease (MBD) a common disease in reptiles. MBD is the collective name given to a number of problems seen in reptiles related to calcium. It is different from calcium deficiency, in which there is a lack of calcium in the body, but MBD is associated with calcium disruption in the body.

Metabolic bone disease can be caused by a number of various sources as well as the combination of various factors.

One cause of MBD is improper levels of calcium in the reptile's diet. Calcium is very important in the building of bones and muscles, as well as the functioning of nerve endings, and when there is not enough calcium in the body problems will arise. Calcium levels, also, affect phosphorus and vitamin D3 regulation within the body, which is why calcium supplements should be given when feeding reptiles.

Improper UV lighting can also cause MBD. Some reptiles need UVB light added to their enclosure. Without the UVB rays, some reptiles such as bearded dragons, iguanas, and mali uromastyx, cannot digest the calcium properly. UVB aids the production of vitamin D3 which is essential in digesting calcium. Most diurnal reptiles, are those that are in need of the extra UV light. Nocturnal reptiles, on the other hand, do not need the UVB rays, but should be given a calcium/D3 supplement at least once a week.

Improper husbandry, is another cause of MBD. Keeping proper enclosure temperatures will help reptiles to digest their foods properly. Being able to properly digest foods is essential in absorbing the nutrients available, including calcium.

Other diseases can increase the chances of a reptile getting MBD. Kidney and liver disease can impair the conversion of vitamin D to an active form. Small intestinal disease disrupts absorption rates. Disease of the thyroid or parathyroid glands can affect calcium absorption since they produce hormones affecting calcium metabolism.

Symptoms of MBD vary with age and degree of the disease.

Most often symptoms of MBD occur as thin, easily broken bones. Thin bones contribute to walking problems, and can hinder jumping and climbing, as the bones become weaker. You may also notice that at the joints, your reptile may not hold its feet properly, causing them to bend backwards.

As bones weaken, the body attempts to strengthen them by laying down connective tissues; this often causes swollen legs.

Breaks may cause twisted and crooked backs, toes, and limbs.

Paralysis can be a symptom, as well. Damage along the spinal cord can cause paralysis of the front or back legs.

Soft, spongy jaw bones, causing eating to become difficult and painful, causing a lack of appetite. A receding jaw line, can also be a sign of MBD.

• Stunted growth is another sign of MBD.
• Trembling and weakness in the limbs, due to damage to nerves.
• Lameness
• Tremors and jerky movements in the toes and legs of the reptile.
• Constipation.

Correcting the diet. This can be a hard task to take in, as reptiles can be set in their ways and resist change.

Oral injection of vitamin D and calcium.

Correcting the temperatures in the enclosure.

Adding a UV light to the enclosure to assist with vitamin D3 production (only necessary with diurnal reptiles). If you have a diurnal reptile, and the enclosure already has a UV light, you may want to change the bulb, as the UV tubes must be changed every 6 months. You may want to consider the UV spot lights, which give out more UV than a tube.

If you do not see any change, see a licensed reptile vet. You should not let the disease progress to a severe state because your pet may not make it through.

You can correct Metabolic Bone Disease if you catch the signs and symptoms early on in the disease.

I am not a practiced veterinarian, and all information posted on this site comes from my experience and knowledge, or that of others I have talked to. For any medical problems that you notice with your reptiles, I recommend making an appointment with a reputable reptile veterinarian as soon as you can.