Influenza A virus (H3N8) in dogs with respiratory disease, Florida.
In 2004, canine influenza virus subtype H3N8 emerged in greyhounds in the United States. Subsequent serologic evidence indicated virus circulation in dog breeds other than greyhounds, but the virus had not been isolated from affected animals. In 2005, we conducted virologic investigation of 7 nongreyhound dogs that died from respiratory disease in Florida and isolated influenza subtype H3N8 virus. Antigenic and genetic analysis of A/canine/Jacksonville/2005 (H3N8) and A/canine/Miami/2005 (H3N8) found similarity to earlier isolates from greyhounds, which indicates that canine influenza viruses are not restricted to greyhounds. The hemagglutinin contained 5 conserved amino acid differences that distinguish canine from equine lineages. The antigenic homogeneity of the canine viruses suggests that measurable antigenic drift has not yet occurred. Continued surveillance and antigenic analyses should monitor possible emergence of antigenic variants of canine influenza virus.
Payungporn
Sunchai
S
Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
Crawford
P Cynda
PC
Kouo
Theodore S
TS
Chen
Li-mei
LM
Pompey
Justine
J
Castleman
William L
WL
Dubovi
Edward J
EJ
Katz
Jacqueline M
JM
Donis
Ruben O
RO
D000595:Amino Acid Sequence; D000818:Animals; D003933:Diagnosis; D004196:Disease Outbreaks; D004283:Dog Diseases / Q000453:epidemiology* / Q000401:mortality / Q000821:virology; D004285:Dogs; D005431:Florida / Q000453:epidemiology; D006385:Hemagglutination Inhibition Tests; D053123:Influenza A Virus, H3N8 Subtype / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000401:mortality / Q000662:veterinary* / Q000821:virology; D010802:Phylogeny; D011024:Pneumonia, Viral / Q000453:epidemiology / Q000401:mortality / Q000662:veterinary* / Q000821:virology; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000401:mortality / Q000662:veterinary* / Q000821:virology; D017422:Sequence Analysis, DNA