Common illnesses of parakeets include tumors, goiters, liver disease and psittacosis states PetPlace.com and BeautyofBirds.com. Parakeets are also susceptible to psittacine beak and feather disease, scaly leg and face mites, polyoma virus and mega bacteria.
Many parakeet illnesses can be treated if they are caught early. Since parakeets are good at hiding their illness, their owner may not realize the bird is ill until it is very sick. Pet bird owners need to be aware of any changes to their parakeets health and behavior. Signs that a bird is sick may include drooping wings, lack of activity and constantly ruffled feathers according to Peteducation.com.