Histomonas meleagridis and Capillarid Infection in a Captive Chukar (Alectoris chukar)

A female, adult, pen-raised chukar (Alectoris chukar) was submitted for postmortem examination. The main gross findings were severe emaciation, coelomic cavity and pericardial edema, and a large, sharply demarcated area of necrosis in the liver. Histologically, the liver lesions were characterized by areas of severe necrosis and inflammation containing numerous protozoal organisms morphologically consistent with Histomonas meleagridis. There was necrotizing typhlitis, with few histomonads and scant Heterakis spp. worms, in the cecum. Numerous aphasmid organisms, consistent with capillarids, were present in the crop and esophageal mucosa. Histomonas meleagridis was identified from frozen samples of liver by polymerase chain reaction and nucleotide sequencing. Sequence analysis of the internal transcribed spacer (ITS)-1, 5.8S, and ITS-2 regions of the ribosomal RNA gene disclosed a 95% identity to a previously sequenced ITS-1, 5.8S, and ITS-2 region of H. meleagridis.