Animal Health Research Reviews

Review Article

Birds and bornaviruses

Susan L. Paynea1 c1, Pauline Delnattea2, Jianhua Guoa1, J. Jill Heatleya3, Ian Tizarda1 and Dale A. Smitha2

a1 Department of Veterinary Pathobiology and the Schubot Exotic Bird Health Center, Texas A&M University, College of Veterinary Medicine and Biomedical Sciences, College Station, TX 77843, USA

a2 Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada

a3 Department of Small Animal Clinical Sciences, Texas A&M University, College of Veterinary Medicine and Biomedical Sciences, College Station, Texas, USA


In 2008, avian bornaviruses (ABV) were identified as the cause of proventricular dilatation disease (PDD). PDD is a significant condition of captive parrots first identified in the late 1970s. ABV infection has subsequently been shown to be widespread in wild waterfowl across the United States and Canada where the virus infects 10–20% of some populations of ducks, geese and swans. In most cases birds appear to be healthy and unaffected by the presence of the virus; however, infection can also result in severe non-suppurative encephalitis and lesions similar to those seen in parrots with PDD. ABVs are genetically diverse with seven identified genotypes in parrots and one in canaries. A unique goose genotype (ABV-CG) predominates in waterfowl in Canada and the northern United States. ABV appears to be endemic in North American waterfowl, in comparison to what appears to be an emerging disease in parrots. It is not known whether ABV can spread between waterfowl and parrots. The discovery of ABV infection in North American waterfowl suggests that European waterfowl should be evaluated for the presence of ABV, and also as a possible reservoir species for Borna disease virus (BDV), a related neurotropic virus affecting horses and sheep in central Europe. Although investigations have suggested that BDV is likely derived from a wildlife reservoir, for which the shrew and water vole are currently prime candidates, we suggest that the existence of other mammalian and avian reservoirs should not be discounted.

(Received September 18 2012)

(Accepted October 01 2012)


  • bornavirus;
  • goose;
  • swan;
  • duck;
  • canary;
  • gull;
  • phylogeny;
  • proventricular dilatation disease;
  • avian


c1 Corresponding author. E-mail: