Bilateral necrotizing pectenitis causing blindness in a rainbow lorikeet (Trichoglossus haematodus).

A rainbow lorikeet (Trichoglossus haematodus) in good physical condition and otherwise neurologically normal was presented with a history of sudden blindness. Gross abnormalities were not detected at necropsy and cultures of aqueous humour and visceral organs failed to yield bacterial growth. In both eyes histopathological examination demonstrated acute necrosis of the pecten associated with a severe heterophilic inflammation and a myriad of Giemsa and Gram-positive, filamentous, branching nocardioform bacteria. In the lungs and kidneys there were several nodules of acute, mild granulomatous inflammation composed of macrophages, giant cells and heterophils. The bilateral nature of the eye lesions was consistent with haematogenous spread of nocardioforms after mild, primary lung infection. The lesions suggest that the vascular network of the pecten may be a site favourable for lodgement of other bacterial species during episodes of bacteraemia or septicaemia.