Photographs from two mallards (Anas platyrhynchos) with trematodiasis

Photographs from two mallards (Anas platyrhynchos) found dead within a warm-water retention pond in Minnesota, US. (A) Jejunum with superficial pseudomembranes and deep mucosal granulomatous inflammation (clear arrow). Small degenerated metazoan parasites are present rarely within the inflamed areas (black arrow). H&E stain. (B). Cecum with approximately 50 x 450-μm diameter adult trematodes (asterisks) burrowed deep into the mucosa. H&E stain.