A mysterious respiratory illness has sickened hundreds of dogs across several states, prompting veterinarians to warn pet owners to take precautionary measures against the potentially deadly infection.

The unusual respiratory illness has been reported in many states, including Oregon, Colorado and New Hampshire. The Oregon Department of Agriculture (ODA) has documented more than 200 cases of the disease in the last three months.

"Based on the epidemiology of the cases reported at this point, the cases appear to share a viral etiology, but common respiratory diagnostic testing has been largely negative. A handful of cases do test positive for M. cynos, but that agent is not believed to be the underlying causative agent," Andrea Cantu-Schomus, communications director with the ODA, said.

The infection begins with symptoms of coughing, sneezing, nasal or eye discharge and lethargy. In some cases, the disease progresses to complications within 24 to 36 hours. The infected dogs may develop a respiratory infection that lasts for six to eight weeks and develop antibiotic-resistant pneumonia.

The infection is likely to spread while in close contact with numerous other dogs in places like daycare, dog parks, groomers or boarding kennels.

Several dogs have died from a severe form of the infection. However, without knowing the exact cause and without a definitive test for detection, determining the number of fatal cases is difficult, Kurt Williams, director of the Oregon Veterinary Diagnostic Laboratory at Oregon State University said. He added that there is no need to panic.

University of New Hampshire senior veterinary pathologist David Needle, who was part of a team that has been investigating the mysterious disease for over a year, said he has not seen a large number of fatalities from the infection.

While labs across the country try to determine the exact cause of infection, dog owners are requested to take certain precautionary measures.

  • Keep pets up to date on vaccinations, including shots against various respiratory illnesses.
  • Keep sick dogs at home.
  • Reduce contact with a large number of unknown dogs.
  • Avoid the use of shared water bowls.