Moisture, warmth, and odor attract flies. If open sores are present, or if thick fur is dampened with urine or feces, flies will head toward these warm incubation areas to lay their eggs. The chances are greater if the rabbit is outside, but it only takes one fly indoors to do the damage. Maggots do not stop at the surface. But instead of being toxin related, these are caused by local nerve sensors on the surface of the body triggering a general or overall nerve reaction, resulting in a seizure.
Rabbits are sensitive to surface irritations.
Our rabbit Phoebe gave us this early warning years ago, in time to save her life. This is never a good sign in a rabbit. It usually means something is seriously wrong. In the case of fly strike, the rabbit may already be in shock. Your course of action will depend on how advanced the infestation is and how far you are from your vet.