title: A retrospective study of circovirus infection in pigeons: nine cases (1986-1993).
abstract: Circovirus infections were diagnosed in 12 pigeons from the United States 4 pigeons from Australia, and 1 pigeon from Canada (1986-1993). Circovirus was identified by electron microscopic examination of basophilic botryoid cytoplasmic inclusions that had a histologic appearance similar to that of psittacine beak and feather disease virus inclusions. Inclusions were seen in splenic, bursal, gut-associated, and bronchus-associated lymphoid tissue macrophages and in bursal epithelial cells. Inclusions were composed of paracrystalline arrays of tightly packed, nonenveloped icosahedral virions 14-17 nm in diameter. Histologic changes in the spleens ranged from lymphofollicular hyperplasia with mild discrete lymphocellular necrosis to lymphoid depletion and diffuse histiocytosis. Lesions in the bursa of Fabricius ranged from mild lymphocellular necrosis to severe cystic bursal atrophy. Remaining histologic findings coincided with concurrent bacterial, viral, fungal, and parasitic infections. Immunoperoxidase staining and DNA in situ hybridization demonstrated that pigeon circovirus is distinct from psittacine beak and feather disease virus; however both viruses apparently share some homologous DNA sequences. Clinical and diagnostic findings indicate that pigeon circovirus may be similar to psittacine beak and feather disease virus with respect to acquired immunodeficiency and subsequent multiple secondary infections.
authors.affiliation: California Veterinary Diagnostic Laboratory System, School of Veterinary Medicine, University of California, Davis 95617.
authors.forename: L W
authors.initials: LW
authors.lastname: Woods
authors.forename: K S
authors.initials: KS
authors.lastname: Latimer
authors.forename: F D
authors.initials: FD
authors.lastname: Niagro
authors.forename: C
authors.initials: C
authors.lastname: Riddell
authors.forename: A M
authors.initials: AM
authors.lastname: Crowley
authors.forename: M L
authors.initials: ML
authors.lastname: Anderson
authors.forename: B M
authors.initials: BM
authors.lastname: Daft
authors.forename: J D
authors.initials: JD
authors.lastname: Moore
authors.forename: R P
authors.initials: RP
authors.lastname: Campagnoli
authors.forename: R W
authors.initials: RW
authors.lastname: Nordhausen
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D001715:Bird Diseases / Q000175:diagnosis / Q000382:microbiology*; D018173:Circoviridae Infections / Q000175:diagnosis / Q000662:veterinary*; D017925:Circovirus / Q000235:genetics / Q000276:immunology / Q000648:ultrastructure; D010856:Columbidae / Q000382:microbiology*; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D007124:Immunoenzyme Techniques / Q000662:veterinary; D017403:In Situ Hybridization / Q000662:veterinary; D008297:Male; D012189:Retrospective Studies
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral