UNUSUAL AND SEVERE LESIONS OF PROVENTRICULAR DILATATION DISEASE IN LORIES

During the early ’90s, anecdotally lories were considered refractory to PDD. Subsequently, the disease has been identified in them. We describe PDD in lories with unusual clinical history, histopathology and virology. Thirteen lories were necropsied during 2011-2016. Clinical history revealed sudden death (5 cases), accident (3), liver pathology (2), and general, nonspecific clinical signs (3 cases) in the week preceding death. None of these cases showed neurological signs or the classical form. Histopathology showed unusually severe and widespread tissue lesions, consisting of massive lymphocytic infiltration and lymphoid nodule formation within and around the ganglia throughout the gastrointestinal tract, in the heart, medullary cords of the adrenal gland, brachial/ischiatic plexus, vagus, and other smaller peripheral nerves and ganglia throughout the body. Proventriculus and liver in paraffin were screened for avian bornaviruses. Primers designed for the ABV matrix gene, that mainly amplify PaBV4, produced negative results. Degenerate primer pairs Mcon and Ncon, that detect most known avian and mammal bornaviruses, produced positive results in all birds examined. It would appear that the lories have a PaBV other than a PaBV4. Sequencing will clarify this point. Despite the presence of ABV, lories were asymptomatic. The severity of lesions may have resulted from a semi-liquid diet that prolonged survival and permitted the development of more extensive lesions, without typical clinical signs.