Mystery respiratory disease sweeping through greyhound population

Dozens of dogs in the U.S. are dying from a mysterious respiratory disease which is sweeping greyhound tracks across the country, and race track owners are being forced to halt racing as researchers hunt for a vaccine to control the outbreak.

A veterinarian in Massachusetts, Dr. Lisa Zerbel, who is treating some of the sick dogs, thinks the illnesses are caused by a new strain of the influenza virus that is more virulent than the common one known as "kennel cough, but other experts are unsure and say it is too soon to pinpoint the cause.

The hardest hit has been Wonderland Greyhound Park, north of Boston, 16 of its dogs have died from the influenza-like illness since the beginning of May, and the track has suspended racing indefinitely and quarantined its 1,200 greyhounds.

According to Massachusetts officials, greyhound deaths have also been reported at racetracks in Colorado, Iowa and Rhode Island in the past month, while other states are seeing a outbreaks of nonfatal cases.

Dr.Zerbel says this could be because greyhounds travel from track to track, and some may be incubating the illness without anyone knowing.

A frustrating aspect of the illness is it tends to be very silent early on, says Zerbel, and it is not until the late stages that they start to show signs indicating that they need treatment, by which time a sick greyhound may be racing at a track in another state.

Autopsies on two of the greyhounds at Wonderland have found that the dogs died of pneumonia, a complication that can be caused by infection by either bacteria or a virus.

Gary Guccione, secretary and treasurer of the National Greyhound Association in Abilene, Kan., says similar outbreaks have plagued racetracks for the past three years, and a major outbreak like this which used to happen once every six or seven years, is now occurring more frequently and with greater strength. Guccione says a good vaccine is desperately needed.

Dr. Alexandra Lightbown,chief veterinarian for the Massachusetts State Racing Commission says there already exists a vaccine for kennel cough, but the Racing Commission does not require it, and it is unlikely it would be effective in this case. In the meantime, all greyhounds at Wonderland are being treated with antibiotics as a preventive measure.

Virginia Tech's Dr. Brad Fenwick, a specialist in greyhound medicine, is leading the search for a new vaccine, and hopes to conduct experiments on a vaccine this summer. Track owners around the country are funding his research.

He doubts the deaths at Wonderland and other tracks are from a new strain of influenza, and says it is unclear yet whether the infections are caused by bacteria or by a virus.

Bacterial pneumonia can result from a variety of illnesses, and in greyhounds it can progress from mild to life-threatening in a matter of hours.

Scott Larrivee, a spokesman for state regulators says at Dairyland Greyhound Park in Kenosha, Wisconsin one-quarter of the track's greyhounds have become ill in recent weeks, though none have died, Dairyland suspended racing this week.

According to Sally Prickett, a state veterinarian, several greyhounds have died at Bluffs Run racetrack in Council Bluffs, Iowa, she is waiting for lab results.

Kennel cough usually hits younger dogs because their immune systems are weaker, but she says this disease is striking older dogs, and appears more serious.