Systemic Amyloidosis in an African Penguin (Spheniscus Demersus) with Bumblefoot

A female, 14-year-old, African penguin (Spheniscus demersus) weighing 2.5 kg with the anorexia for one day and 22 months history of bumblefoot was found dead in aquarium. Grossly, severe bumblefoot in the central surface of the right foot, severe enlarged liver and kidneys with orange color were observed. Histopathologically, pinkish amorphous materials were accumulated in liver, spleen, kidney, and stomach. The pinkish materials in the liver, kidney, spleen, and stomach were confirmed as amyloid with typical orange color reactions using Congo red stain under the light microscope and with bright red color expressions using Congo red stain under the fluorescence microscope. Based on the typical gross and histopathologic findings and special staining, this case was confirmed as systemic amyloidosis. A long period time of moderate bumblefoot might be closely associated with the occurrence of systemic amyloidosis in the captive penguin.