Rabies, the most important viral disease, is found in these mammals. Both furious and dumb forms have been reported in vampire bats. Most bats may recover from rabies infection. Some bats, however, become carriers of this disease and may shed virus in the saliva for up to 16 months. The important clinical signs of rabies in bats include aggressiveness, restlessness, resting on the ground, biting of inanimate objects, difficulty in swallowing food or water and unusual daytime flying. Captive bats should be vaccinated with inactivated tissue culture vaccines. Salmonellosis has been reported in bats. Infected animal shows the clinical symptoms of high rectal temperature, anorexia, depression, enteritis and septicaemia. Bats may be the carriers of parasites (e.g. Trypanosoma cruzi and T. equinum) causing trypanosomiasis. Toxoplasmosis has been reported in bats. Infected animal shows chronic febrile syndrome. Bats may infest with a great variety of flukes (e.g. Ophiosacculus mehelyi and Prosthodendrium dinanatum). Nasal mites are found in bats. A large number of external parasites are also found in these animals. Bats infested with external parasites may be treated with malathion and DDT. Free filarid worms are found in the peritoneal cavity of many long-tongued and short tailed fruit bats. Toxocariasis caused by Toxocara pteropodis has been reported in island flying fox (Pteropus hypomelanus). Dilated cardiomyopathy caused by hypovitaminosis E has been reported in flying fox. The clinical signs include lethargy, anorexia, hypothermia, reluctance to fly and cranial oedema.