Metabolic bone disease (MBD) is a common illness in captive tortoises and other reptile species. The disorder can damage to a tortoise’s shell and bone structure. It can cause permanent damage and deformity or even death, if left untreated.
What Causes Metabolic Bone Disease
Metabolic bone disease is typically caused by very low levels of calcium or vitamin D over a long period of time. In some cases, the levels of phosphorous may be too high.
Russian tortoises need UVB rays to synthesize vitamin D, which is important for the body to absorb calcium and phosphorus. Both calcium and phosphorus are essential for strong bones and muscles. Without UVB for prolonged periods of time, tortoises can develop MBD.
Signs of Metabolic Bone Disease
- Unsteady walk or limping
- Bowed legs
- Too big for the shell (shell appears too small for body)
- Soft or flexible lower jaw
- Soft shell
- Pyramiding
- Hard lumps along the legs, spine or jaw
- Difficulty standing or moving
- Twitching, tremors, seizures
- Hind end weakness
- Lethargy
- Lack of appetite
- Constipation
- Death
How to Treat Metabolic Bone Disease
Depending on the severity of the disorder, the treatment will vary.
For minor or mild cases, tortoises will generally recover with dietary changes and husbandry improvements. Ensure that the tortoise is getting proper calcium supplementation. For outside tortoises, use a calcium without D3, but for a tortoise housed inside, use a calcium with D3.
For indoor Russian tortoises, ensure that the enclosure has a source of UV that is still outputting proper amounts of UVB. Old bulbs or UVB tubes will not produce enough UVB rays to benefit your tortoise.
Use a solar meter to measure the UV output for indoor UV sources.
For more severe cases of MBD, the tortoise will need calcium and vitamin D injections, oral supplements, fluid therapy and/or a nutritional support. Splints may be necessary for any broken or damaged legs.
Prevent MBD in Tortoises
The best way to prevent metabolic bone disease in tortoises is proper supplementation and husbandry.
When feeding a Russian tortoise, offer a varied diet with regular supplements.
And when housing a Russian tortoise inside, ensure proper UV lighting is set up. Change the UV source regularly. Use a solar meter to ensure that the UV source is still emitting proper UV.
