Metabolic Bone Disease (M.B.D.)

Usually suffered by basking diurnal lizard species, most commonly
encountered in Green Iguana's & Water Dragons.

Causes:

A combination of poor husbandry and improper nutrition.
The lack of calcium, also the lack of Vitamin D3, This is Usually acquired from the sun, so be sure to provided a suitable U.V.B. fluorescent tube with an output of no less than 5% to compensate, (UV light is necessary for vitamin D synthesis which is necessary for calcium to be absorbed).

Symptoms:

Swollen limb joints, shaking / tremors, lethargy, limping, soft bones and loss of appetite. This is a life-threatening disease, so consult a vet as soon as possible.