Thinking of the dog park? Think twice: Mystery dog illness in L.A. spurs warnings by officials

A man with a puppy on a sidewalk near a homeless encampment
Kwane Stewart, a veterinarian, checks on a puppy in L.A.’s Skid Row district this year.
(Genaro Molina / Los Angeles Times)
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Los Angeles County public health officials are investigating a mysterious respiratory illness affecting a rising number of dogs. Its origin, transmission and treatment are unknown.

Reported incidents of the disease have emerged in several states, including Colorado, Oregon and New Hampshire, and it has been fatal in some instances.

At least 10 cases have been reported to the L.A. County Department of Public Health since Thursday. The affected dogs have ranged in age from 9 months to 11 years, the department said. Some have been ill since the beginning of October, and one dog died of the disease, officials said. Two others have recovered.


There is no specific diagnosis for the illness. Rather, veterinarians make the determination when evaluating a dog who is suffering respiratory symptoms but tests negative on a panel of common diseases with similar symptoms, such as kennel cough.

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The diagnosis also requires the dog to have either acute pneumonia that progresses rapidly, chronic pneumonia that is not responsive to antibiotics, or a respiratory infection for at least six weeks with little to no response to antibiotics.

The illness, which investigators refer to as atypical canine infectious respiratory disease (aCIRD), causes symptoms such as coughing, sneezing, nasal discharge and lethargy. Public health officials warn the public to monitor their pets for such symptoms and, if they display them, to take them to a veterinarian to be evaluated.

Officials also recommend isolating the sick dog at home for at least 28 days after it first becomes ill, and quarantining the animal for at least 14 days from other dogs in the household to prevent the spread. Though it is unknown how the disease spreads between animals, public health officials recommend keeping the dog away from pet day-care centers, grooming facilities, boarding kennels and dog parks, as they may be vectors for disease spread.

Meanwhile, health researchers have been looking for clues to the disease.

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NBC News reported that researchers with the University of New Hampshire’s Veterinary Diagnostic Laboratory and the school’s Hubbard Center for Genome Studies may have identified a bacterium responsible for the symptoms. It is unknown, however, whether the pathogen is responsible for all instances of the disease.

The Oregon Department of Agriculture, on the other hand, suggests the infection is viral in nature due to the ineffective response to antibiotics, which don’t work against viruses.