Feather Discoloration Due to Saprophytic Fungal Growth

Summary: Feather discoloration in psittacines has been attributed to aging of feathers, delayed moult, malnutrition, hypothyroidism, and often to liver disease.1 Feather discoloration due to soiling and subsequent saprophytic fungal growth has been described in flamingoes at Slimbridge England.2 Feather Fungus in Flamingoes This phenomenon was also observed at Parrot Jungle and Gardens in Miami after a dietary change, which increased the fat content of the diet. The flock of 57 Caribbean flamingoes was housed in a large open-air exhibit approximately 1 acre, with a large fresh water lake. The birds remained almost exclusively in the open sunny center of the exhibit adjoining the lake. The exhibit was surrounded by a well maintained but dense garden. Addition of a high quality dog food to the diet was intended to improve reproductive performance in the stable flock of flamingoes. The dietary change was followed by onset of the rainy season. Flamingoes engaged in nest building activities also tend to soil their plumage with mud used to construct mounds. The plumage, primarily of the back and wings, developed a dark discoloration appearing streaked with black. Physical exam revealed oily deposits coating the feathers with grossly visible opaque black coloration. Microscopic examination revealed black deposits on plumules often with corresponding degeneration of pennaceous barbs and barbules. Culture of feathers revealed several species of saprophytic fungi which are also associated with sooty mold,