DVMs halt client fears of WNV epidemic in dogs

The first fatal case of West Nile Virus (WNV) in the canine population will not snowball into an equine-like epidemic, veterinarians say.

"I don't think we're in a panic mode at all," says Dr. MichaelGarvey, director of the Bobst Hospital of the Animal Medical Center in NewYork. Although the death of an 8-year-old Irish Setter/Golden Retrievermix in Illinois shows "that this dog in Chicago was sufficiently ill[with WNV] ... I still don't think this virus is going to be a big problemin dogs."

The WNV-confirmed death of a U.S. canine was a first. Dr. John Andrews,director of the University of Illinois Veterinary Diagnostic Laboratoryat Urbana-Champaign where the virus was discovered, reported the case. (Theonly previously reported canine case occurred in 1977 in Botswana, Africa.)Since the announcement, isolated reports of dog exposure have arisen inGeorgia, Nebraska and Virginia.

Next year poses no greater threat of WNV in pets than this year, accordingto Garvey. "What I've read to date suggests that not all species areequally susceptible to this virus. Humans, for example, seem to be quiteresistant, even though we've had a few deaths. But I think dogs and catsat this point are felt to be more resistant than even humans."

"If we do see more cases, it will be rare," says Dr. ChristineMerle, clinical assistant veterinarian at the continuing education publicservice unit at University of Illinois.

Not necessarily, Andrews cautions. "Since we now have found it inone dog and the WNV season is still with us, WNV infection is now suspectedwith nearly any dog that exhibits neurologic symptoms. Until the laboratoryexams are completed, we do not know how many of these cases are actuallyWNV infection."

As for development and marketing of a pet-specific WNV vaccine, New Yorkersdefinitely won't buy it, Garvey says. "We've had the virus out herefor three years, and I don't think anybody has even got a suspicion of onecase. So who would we vaccinate?"

More cautious

Some veterinarians don't entirely discount the disease. Dr. Jeff Shell,in Marietta, Ga., says he expects the virus to get worse, so it warrantsa vaccine. "You may save one out of 1,000 lives, but if it's your pet,you'll do it."

Andrews, of the lab where the case was confirmed, also cautions, "Myunderstanding of the epidemiology suggests that the problem will be of alesser magnitude next year, but it will still be with us."

As to whether a vaccine is necessary, he adds, "Since the only experimentalinfections of dogs, of which I am aware, resulted in no disease, it maybe very difficult for a vaccine manufacturer to demonstrate the necessaryefficacy to get a vaccine approved and marketed."

Andrews says he expected WNV would eventually afflict the canine population,although taking part in the discovery himself was "sort of like winninga lottery. You know someone is going to find it, it's just surprising thatwe did."

Scattered incidence

In Nebraska, Dr. Jerry Upp discovered his state's first case of WestNile in a dog. "It didn't surprise me too much to have one in our particulararea, because our county is over-represented on the equine side with WestNile," he says.

The dog, a 5-year-old Golden Retriever, presented lethargic and limpingwith inappetence and unusual aggression. Upp prescribed antibiotics; thefollowing day the dog returned to being playful.

Upp ran bloodwork on the dog, sending results to Antech Diagnostics.The lab later confirmed exceptionally high titers for WNV.

"It was a pretty fast progression through this dog. I'm sure hisimmune system helped me (save him) more than anything," Upp says.

Andrews suspects tens of thousands of dogs in the United States havebeen exposed to WNV since 1999. "With that rate of exposure, it wouldtherefore be likely that eventually we would find a dog seriously affectedwith WNV in the U.S."

As news of canine WNV cases has infiltrated veterinary exam rooms nationally,practitioners have expressed newfound awareness, little fear and tracesof annoyance.

Dr. Gary Brummet, an Urbana practitioner near UI, says his mission isto relay reliable information to his clientele."When clients call,I explain the symptoms of West Nile Virus, and most of the time they'recalling about symptoms that would have no neurological basis or have anythingto do with West Nile," he says. If the symptoms sound familiar, heoffers to run tests.

Merle feels the Illinois WNV case helped raise awareness, but she hesitatesto point to any trend.

"We did know dogs can become infected, but we never realized thatit caused clinical illness to the degree we've seen where death was theresult of it."

Shell says he just wishes clients were better informed about "realthreats" for pets. "Some people say, 'I just want to be rational.Is there anything I need to worry about?' You give them an answer and they'refine. Then, some people, when we tell them there's more important thingsto worry about, like heartworm preventatives and getting your dog spayedor neutered, they still remain paranoid about West Nile."

Angell Memorial Hospital in Boston declined comment because the hospitalsays it has had no contact with the disease.