Morphopathological characteristics of histomoniasis in Japanese quails (Coturnix coturnix japonica)

Histomoniasis is a disease caused by a protozoan parasite belonging to the trichomonas group which is prevalent all over the world. Nine Japanese quails (Coturnix coturnix japonica) with history of depression, anorexia, ruffled feathers, lethargy and watery yellowish diarrhoea were referred to the clinic. The client claimed that 12 quails with similar signs died during the last 8 days and the other remaining quails were at risk. Postmortem examination revealed caseous exudate in the coelomic cavity, swollen liver with yellowish white nodules and distended caecum with multifocal, slightly elevated, yellow lesions in the wall. Microscopically, diffuse necrotising hepatitis and severe typhlitis associated with numerous intralesional Histomonas trophozoites, infiltrated inflammatory cells were observed. Degenerated trophozoites were also identified in the necrotic areas. These gross and microscopical features are characteristic of histomoniasis