Fig. 2.

Gross lesions of high pathogenicity avian influenza virus H5N1-infected birds during the 2021–2022 season.

Lesions observed including pancreatic necrosis, commonly multifocal to coalescing tan discoloration and occasionally haemorrhagic (arrowheads; duck, a), petechiae on the coelomic fat (arrowheads; chicken, b), haemorrhage on the proventricular mucosa centred on the proventricular ducts (arrow; chicken, c), and haemorrhages on the intestinal serosa (arrow, mesenteric border) and on the mesentery (arrowheads; chicken, d).