Unusual high frequency of Aspergillosis on wild Magellanic Penguin (Spheniscus magellanicus) in southern Chile.

GODOY, CLAUDIA; LARENAS, JULIO; BOERSMA, DEE; GARCÍA BORBOROGLU, PABLO

Bristol

Conferencia; 8va. International Penguin Conference; 2013

University of Bristol

Aspergillosis is a common disease of captive penguins at zoos and rehabilitation centers. Necropsies show that Aspergillosis is the main cause of death for captive Magellanic penguins (Spheniscus magellanicus) but the frequency of Aspergillosis on wild penguins is unknown. From December 2010 to March 2011 and October 2011 to February 2012, we determined the cause of death of Magellanic penguins on Magdalena Island (52°55’S; 70°34’W) located in the Magellan Strait, Chile. We found that 14% of the penguins (8 chicks and 1 adult) had macroscopic lesions indicative of Aspergillosis (N=65, 44 chicks and 21 adults). For diagnosis we used exudative or caseous secretion in the trachea, air sacs thickened and/or with caseous secretion and multiple granulomatous nodules in lungs. These 9 penguins presented two or more of these lesions. Histopathological examination in the air sacs and lungs using haematoxylin-eosin stain results were consistent with Aspergillosis. Eight of the 65 dead penguins had lung granulomas and five of the 9 penguins with the macroscopic lesions have fungal structures. Out of the 9 penguins that had Aspergillosis, 8 were in poor body condition, as evidenced by their light weight, small pectoral muscle bulk and lack of subcutaneous fat. The Aspergillosis infection may benefit from nutritional deficiency and a depressed immune system. Two chicks of these 9 penguins had multiple proliferative cutaneous nodular lesions too and we suspected they had Avian Pox Virus. We confirmed the diagnosis with a histopathological examination from skin sample showing intracitoplasmic inclusion bodies and globous and degeneration of keratinocytes. This disease affects individuals with depressed immune systems and there are no previous reports of wild penguins affected by both diseases simultaneously. Aspergillosis frequency at Magdalena Island is higher than the 3,3% to 4,1% reported for dead Blue Penguin (Eudyptula minor) in the wild. At Magdalena Island penguins nest in very deep humid burrows that may facilitate the development of fungal infections when penguins have nutritional deficiencies and the immune response is vulnerable.