Trichomonosis due to Trichomonas gallinae infection in barn owls (Tyto alba) and barred owls (Strix varia) from the eastern United States.

Trichomonosis is an important cause of mortality in multiple avian species; however, there have been relatively few reports of this disease in owls. Two barn owls (Tyto alba) and four barred owls (Strix varia) submitted for diagnostic examination had lesions consistent with trichomonosis including caseous necrosis and inflammation in the oropharynx. Microscopically, these lesions were often associated with trichomonads and molecular testing, if obtainable, confirmed the presence of Trichomonas gallinae, the species most commonly associated with trichomonosis in birds. The T. gallinae genotype in one barn owl and two barred owls was identified as ITS-OBT-Tg-1 by sequence analysis. Columbids are the primary hosts for T. gallinae, and columbid remains found within the nest box of the barn owls were the likely source of infection. This study is the first to formally describe the strains and genetic variation of T. gallinae samples from clinical cases of trichomonosis in barn and barred owls in the eastern USA.