A rare outbreak of dog flu has swept through a kennel in southern California, raising concerns over the possible spread of an untreatable virus, animal control officials said.

The disease, a type A influenza virus called H3N8 by scientists, is believed to have mutated from a horse flu common at racetracks where it leapt to greyhound dogs in the state of Florida in 2000.

The virus, however, does not appear to be transferable humans, experts said.

"Horses have had this disease for 40 years," said Doctor Gundula Dunne, of the San Diego County Animal Disease and Diagnostic Lab. "But this is relatively new in dogs and they have no immunity," told AFP.

No vaccine is currently available for the dog flu, and it cannot be treated by any specific drug, said Dunne.

The flu spread like wildfire at the facility run by Canine Companions for Independence, an organization that pairs trained dogs with the disabled that is based in Oceanside, a small town south of Los Angeles.

Two dogs have tested positive for the virus and the 62 other dogs in the kennel are displaying characteristic symptoms of coughing and sneezing. All dogs at the facility have been quarantined.

While humans are not thought to be at immediate risk from the virus, influenza changes continuously and further species mutation cannot be completely ruled out, Dunne warned.

"Because there is not enough data out there in the regular dog community, it is hard to say what the fatality rate may be," said Dunne. She estimated a death rate between one and five percent and urged California dog owners to wash their hands and steer clear of coughing canines. — AFP