Amyloidosis, Hemochromatosis, and Atherosclerosis in a Roseate Flamingo ( Phoenicopterus ruber )

An aged male roseate flamingo, in a private collection in the British Virgin Islands, was found acutely "down." After four days of supportive therapy, the flamingo succumbed. At necropsy gross lesions included emaciation; collapsed and thickened, yellow abdominal air sac; dark red liver, partially covered by friable yellow material; and a raised, intimal plaque in the aorta near the iliac trifurcation. Histologic examination revealed severe, diffuse, pyogranulomatous air sacculitis with associated locally extensive pleuroperitonitis/perihepatitis. Pansystemic, predominantly periarteriolar distribution of amyloid deposition was evident, as was massive intrahepatocellular accumulation of iron pigment (hemachromatosis/hemosiderosis). A locally extensive, nonobstructive, fibroatheromatous plaque was present in the distal aorta. Amyloidosis, hemochromatosis/hemosiderosis, and atherosclerosis have been recognized in Phoenicopteriformes and other marine or aquatic birds. Their pathogenesis and pathogenicity remain a matter of debate.