title: Evolution of canine and equine influenza (H3N8) viruses co-circulating between 2005 and 2008.
abstract: Influenza virus, subtype H3N8, was transmitted from horses to greyhound dogs in 2004 and subsequently spread to pet dog populations. The co-circulation of H3N8 viruses in dogs and horses makes bi-directional virus transmission between these animal species possible. To understand the dynamics of viral transmission, we performed virologic surveillance in dogs and horses between 2005 and 2008 in the United States. The genomes of influenza A H3N8 viruses isolated from 36 dogs and horses were sequenced to determine their origin and evolution. Phylogenetic analyses revealed that H3N8 influenza viruses from horses and dogs were monophyletic and distinct. There was no evidence of canine influenza virus infection in horses with respiratory disease or new introductions of equine influenza viruses into dogs in the United States. Analysis of a limited number of equine influenza viruses suggested substantial separation in the transmission of viruses causing clinically apparent influenza in dogs and horses.
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA.
authors.forename: Pierre
authors.initials: P
authors.lastname: Rivailler
authors.forename: Ijeoma A
authors.initials: IA
authors.lastname: Perry
authors.forename: Yunho
authors.initials: Y
authors.lastname: Jang
authors.forename: C Todd
authors.initials: CT
authors.lastname: Davis
authors.forename: Li-Mei
authors.initials: LM
authors.lastname: Chen
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Dubovi
authors.forename: Ruben O
authors.initials: RO
authors.lastname: Donis
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D004283:Dog Diseases / Q000821:virology*; D004285:Dogs; D019143:Evolution, Molecular; D006734:Horse Diseases / Q000821:virology*; D006736:Horses; D053123:Influenza A Virus, H3N8 Subtype / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009976:Orthomyxoviridae Infections / Q000662:veterinary* / Q000821:virology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014481:United States
chemical_list: D012367:RNA, Viral