For example, a type of filarid worm is native to the United States, and its host is the grackle. It rarely causes problems with native birds, however, this worm has caused great losses among juvenile emus. Emus, being large, flightless birds from Australia, have no inherent immunity to the filarid worms. The emu chick, if bitten by a gnat that has bitten an infected grackle, will develop neurological signs and will likely die. The penguin also suffers by being transplanted from its normal habitat.
Malaria causes tremendous problems in penguins at many zoological parks and gardens.
Because these flightless birds have never been exposed to malaria in their native cold climates, they have no immunity to it. Instead of succumbing to sarc, many macaws, conures and amazons may have cysts in muscle tissue that are found incidentally at necropsy and histopathology when a bird has died of other causes. Sarcocystosis Let's now go through exactly how this parasite gets into a susceptible bird and what it does once it gets in there. When the opossum sheds the parasite in the feces, it may be mechanically transported by cockroaches or flies that have visited opossum droppings. If these insects then find their way into an aviary, there are several ways that they can spread disease to psittacines.