Polyglucosan storage disease in a black-capped parrot (Pionitesmelanocephalus)

Following an episode of sudden lethargy, an 18-month-old female black-capped parrot (Pionites melanocephalus) died while being examined. On gross examination, there was fluid within the coelom, hepatomegaly with yellow colouration and the heart appeared enlarged with pallor throughout the myocardium. On histological examination, cardiomyocytes were swollen with loss of cross striations and contained 6-12-μm diameter intrasarcoplasmic pale grey inclusions of storage material. Cardiomyocytes were occasionally karyomegalic with mitotic figures, lost or replaced by fibrosis and inflammation. Within the liver, there was periportal and centrilobular fibrosis and mild lipid-type vacuolar change with extramedullary haematopoiesis. In the lung, the bronchi and parabronchi had luminal haemorrhage and oedema with hypertrophy of epithelium lining the parabronchi. On transmission electron microscopy, the storage material was non-membrane bound, fibrillar and intrasarcoplasmic and had an occasional homogeneous, electron-dense, central core. The morphological features of this material, combined with the histological findings, are consistent with a diagnosis of polyglucosan storage disease and subsequent heart failure.