Novel siadenovirus infection in a cockatiel with chronic liver disease

•A novel siadenovirus was isolated from a cockatiel with chronic hepatopathy.•Next generation sequencing assembled a contiguous sequence including the hexon gene.•Phylogenetic analysis demonstrated a close relationship to a budgerigar adenovirus 1.•This isolate is a distinct siadenovirus; proposedly, psittacine adenovirus 5 (PsAdV-5). A 15-year-old female cockatiel (Nymphicus hollandicus) undergoing long term management for hepatopathy died and underwent necropsy. Microscopic findings were consistent with chronic liver disease characterized by distorted hepatic architecture, fibrosis and biliary proliferation. The additional finding of large intranuclear inclusion bodies within hepatocytes and renal tubular epithelium prompted diagnostic next generation sequencing. The assembled sequences isolated from pooled kidney and liver were related to siadenoviruses. The genus Siadenovirus, within the family Adenoviridae, includes several species of viruses that pathogenically infect avian species including hemorrhagic enteritis virus of turkeys and marble spleen virus of pheasants. Siadenoviruses have previously been reported in seven psittacine species: a plum-headed parakeet (Psittacula cyanocephala), an umbrella cockatoo (Cacatua alba) budgerigars (Melopsittacus undulates), an eastern rosella (Platycercus eximius), a scarlet chested parrot (Neophema splendida), a cockatiel (Nymphicus hollandicus), and a red-crowned parakeet (Cyanoramphus novaezelandiae). This report describes a novel siadenovirus in a cockatiel that is highly identical to budgerigar adenovirus 1 and distinct from PsAdV-2 in cockatiels. We report the clinical pathologic, gross, and histopathologic findings in a cockatiel with chronic hepatitis and a novel siadenovirus, PsAdV-5. The sequencing data is presented with a phylogenetic analysis.