Background: Leucocytozoonosis is a disease of birds caused by obligate intracellular protozoa of the genus Leucocytozoon. We determined the prevalence of Leucocytozoon spp. using light and transmis-sion electron microscopy in domestic birds in southwest of Iran.
Methods: A total of 825 blood smears from 275 birds were examined for presence of infection. The structure morphology of Leucocytozoon spp. was studied using light and electron microscopy.
Results: Forty-four (16.0%) of the birds were positives for Leucocytozoon. The detected parasite were found in 14 chickens (5.1%), 12 geese (4.3 %), 10 ducks (3.6%), and 8 turkeys (2.9%). The majority of the records were from the northeastern regions.
Conclusion: Leucocytozoonosis are distributed in the Lorestan province bird population and elec-tron microscopy can resolve the problem to distinguish between similar species of Leucocytozoon.