Horse Flu Virus Jumps to Dogs.

This article focuses on a study related to epidemiology. Mankind may be worried about a worldwide outbreak of influenza, but man's best friend is already in the midst of one. A dangerous flu virus originating in horses is spreading fast among U.S. dogs and may circle the globe, researchers say. With very few exceptions, dogs seemed resistant to influenza, says Edward Kilbourne, a retired flu researcher at New York Medical College in New York City, who published rare evidence of a human flu strain infecting six dogs in New York in 1975. The current outbreak, described in a paper published online by Science this week, came to light after 22 greyhounds developed a respiratory disease, and eight died, at a Florida racetrack in January 2004. The researchers found that it belongs to the H3N8 strain, which causes influenza in horses worldwide. Its sequence is 96% identical to that of other circulating H3N8 strains, suggesting that the entire virus jumped the species barrier, without reassorting with another strain first.