Gizzard nematodiasis in Japanese mountain hawk eagle (Spizaetus nipalensis)

In this paper, we report spontaneous gizzard nematodiasis in an adult Japanese mountain hawk eagle (Spizaetus nipalensis). Grossly, the gizzard had a black mucoid substance attached to the surface mucous membrane, and the heart was dilated. Histologically, immature larvae with yellow pigments invaded crypts of the mucous membrane. More developed larvae invaded the lamina propria and muscular layers and serosa of the gizzard, with pressure atrophy and cellular reaction (infiltration of heterophils and macrophages and proliferation of fibrous connective tissue). Moderate bronchopneumonia due to larvae invasion was also seen in the lung. The morphology suggests that the parasites may be nematodes, but the species of nematode could not be confirmed. The bird may have died from malabsorption and respiratory damage as a result of the gizzard and lung lesions.