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Avian Hematozoa

Hemosporidiosis, Avian Malaria

Avian hematozoa is parasitic disease of ducks, caused by protozoan blood parasites of the order Hematozoa. The parasites are transmitted to ducks through various insect vectors, which include black flies (Simulium spp), louse flies (Ornithomyia spp), biting midges (Culicoides spp), and mosquitoes (Culex, Aedes spp). These insect vectors are most likely to feed on the exposed flesh around the eyes, the beak, and on the legs and feet of the bird. However, many of the biting flies can crawl beneath the duck's feathers to reach the skin surface.

Ducks, geese, swans and other waterfowl are highly susceptible to infection and over 75 percent of wild waterfowl species are reported to be infected with hematozoa parasites. The three genus most commonly reported in waterfowl include Leucocytozoon, Haemoproteus, and Plasmodium. Wild turkeys in the eastern United States are also frequently infected by these parasites. If ducks have any existing parasitic infections, they are more at risk of a secondary infection resulting from immunosuppression.


Weight loss
Loss of appetite
Difficulty breathing


  • History
  • Clinical signs
  • PCR


MethodMethod Summary
Supportive careIsolate the bird from the flock and place in a safe, comfortable, warm location (your own duck "intensive care unit") with easy access to water and food. Limit stress. Call your veterinarian.
Primaquine0.75–1 mg/kg PO once, use with chloroquine (25 mg/kg at 0 h, then 15 mg/kg at 12, 24, and 48 h)



Risk Factors

  • Ducks living in tropical or subtropical regions.
  • High abundance of insects
  • Presence of a natural water body nearby
  • Influences of climate change
  • High populations of wild ducks on the premises or nearby