Pneumonia

A rabbit well cared for and properly fed rarely encounters this serious illness. Keep the rabbit's environment consistent, including the ambient temperature; sudden changes in temperature diminish a rabbit's natural resistance. A listless, unhappy, unhungry bunny requires your attention, as these are signs of pneumonia, in addition to mucus around the mouth and nasal passages. The assistance of a vet is essential, as most rabbits die within a few days of contracting the illness.