Aberrant Clinical Appearance and Pathomorphology Noticed During an Outbreak of Histomonosis Indicates a Different Pathogenesis of Histomonas meleagridis Genotype 2.

The present case report describes a remarkable feature of Histomonas meleagridis characterized by aberrant clinical appearance and pathomorphologic lesions, which were mainly confined to the ceca, noticed during a field outbreak of histomonosis. In a flock of meat turkey toms, sudden death was noticed at the end of week 5 in the absence of specific clinical signs. Instead of the well-known sulfur-colored feces, some caseous cores were found in the litter.