Mystery outbreak in 150 dogs at a local veterinarian in Colorado - 1st May 2011

DURANGO, COLO. — About 150 dogs in Durango, Colo., have fallen ill with what one local veterinarian can only call a "mystery."

"We're in a tourist town, so generally after the holidays, there's a little surge of kennel cough," says Dr. Stacee Santi, managing veterinarian at Riverview Animal Hospital in Durango.

But around mid-February, she started seeing a "skyrocketing" number of dogs presenting with a cough much thicker than those suffering from kennel cough and some that had progressed to pneumonia.

"It was really bizarre," she says, adding the dogs typically were not responsive to antibiotic treatment.

At a quarterly meeting of the Four Corners Veterinary Association, comprised of all the veterinary practices in Durango, Santi discovered that other veterinarians in town were seeing the same thing. About 150 in all—50 at her practice alone—are suspected to have succumbed to the mystery ailment, but none died and all have made full recoveries after about three weeks.

The primary complaint of clients was the dog's cough, but Santi says symptoms also included low-grade fever, nasal discharge varying from clear to thick and occasional conjunctivitis. The coughing ranged from a dry cough similar to that found with kennel cough turning into a more moist cough, Santi says.

About 75 percent of the dogs identified to be suffering from clinical symptoms of the same ailment had spent time at a local dog daycare facility, but a number of the center's "regulars" showed no symptoms. Santi says the owner's dogs—who regularly attend the daycare—have not gotten sick.

Veterinarians in neighboring towns have not seen any cases, either, Santi says.

"I don't know if we're dealing with a new virus that hasn't been isolated or a new form of the flu. At this point it's kind of up in the air," Santi says.

Samples were sent to the U.S. Department of Agriculture and other veterinary epidemiologists, but experts have not confirmed the ailment yet, she says.

About three-quarters of the samples were negative for everything, and others had some positives for more common infections, but the results were not consistent for any one particular problem, Santi explains. The samples have been negative so far for H3N8, canine influenza. Santi consulted with Dr. Cynda Crawford of the University of Florida College of Veterinary Medicine, who told her canine flu has not been found to mutate yet.

"She doesn't think we're dealing with a new strain," says Santi. "So at this point we're moving forward."

Testing is now being done for H1N1, "but everyone seems to pretty much think it's a long shot." Read More