Wait, adjust, or see a vet
Wait if it is a healthy adult that skipped a day or two of insects but still eats greens and looks well.
Adjust if the basking surface is below 105°F, there is no T5 HO UVB, or something changed recently: a new enclosure, a move, another pet nearby, a lot of handling.
See a reptile vet if it refuses food for more than 3–4 days (sooner for a juvenile) and also loses weight, looks thin at the tail or limbs, has sunken eyes, is lethargic, or has abnormal droppings.
The usual causes
- Too cool. The basking surface should read 105–115°F, with the cool end at 70–85°F. Two 90–100 W halogen bulbs usually do it.
- No or weak UVB. A 22 inch T5 HO 10–12% tube on the warm side, about 11 inches above the dragon through mesh.
- Stress. A new home, rearranged enclosure, other pets in view or too much handling.
- Brumation. A seasonal slow-down in adults; see bearded dragon brumation. It is rarer in captivity than people think.
- Illness or impaction. Parasites, infection, metabolic bone disease, or swallowed loose substrate. These need a vet.