Love Your Pet: Is There a Mysterious Respiratory Illness in Dogs?

Lately, I have watched a scare among dog owners nationwide concerning reported cases of a mysterious respiratory illness in dogs that is supposedly killing our pets. Worse, these reports say there is no known cause or treatment.

Rumors of new illnesses can strike fear into pet owners’ hearts.

I first heard about this from a friend who saw it on the TV news, and I was very concerned but also baffled that I had not heard of the problem until then. On December 22, 2023, a Thomson Reuters news service article titled, “US finds no novel pathogens in genetic testing of mystery illness in dogs,” that a “mysterious respiratory illness [is] affecting dogs,” but tests show no “new pathogens.” It said, “The illness has sickened dogs in at least 14 states. It can last four to six weeks and cause mild bronchitis, which could escalate to pneumonia.”

Likewise, the American Kennel Club published an article in December called “Unknown Canine Respiratory Illness: What We Know So Far,” which read, “Outbreaks of an unknown canine respiratory illness have been becoming increasingly prevalent as noted in the media over the past few months in many states across the United States. Especially this time of year, increased respiratory infections are reported among dogs, but this particular one doesn’t yet have a name – or a clear cause or treatment. Owners are reporting symptoms that mainly include prolonged coughing, lethargy, and change in appetite.”

The article said the American Veterinary Medical Association first reported cases of the “mystery” canine respiratory illness in August 2023 around Portland, Oregon. “From mid-August to mid-November, more than 200 cases of this illness were reported.” It continued, “National numbers are not known exactly because states have different reporting requirements, but cases of this canine respiratory illness have been found in Colorado, New Hampshire, and Oregon. Reuters recently reported that potential cases of the canine respiratory illness have been found in California, Florida, Georgia, Illinois, Indiana, Maryland, Massachusetts, Rhode Island, Vermont, and Washington.”

I decided to do my own research and contacted our Veterinary Information Network – a worldwide source of veterinary information. This “mystery illness” was supposed to have appeared in New England, but veterinarians in that area did not know anything about it. A specialist even stated that sporadic reports turned out to be influenza or parainfluenza, which can progress to pneumonia but typically are mild and self-resolving. In his words, “There’s no need for a TV news story.”

I then asked local drug representatives who travel from hospital to hospital, and they had not seen or heard of a problem, either.

‘Testing of the mysterious respiratory illness affecting dogs across the United States has not yet revealed any new pathogens or any common cause.’

There are many causes of respiratory illness in dogs. The most common are part of what we call the Canine Respiratory Disease Complex. This is a group of pathogens, both bacterial and viral, that can cause a pet to become sick. Most dogs are treated with supportive care and sometimes antibiotics and cough suppressants. Some pets receive nebulization therapy or breathing treatments to convey medication more quickly down the air passages. To try to find the cause of a pet’s illness requires both an examination and testing. Testing includes radiographs of the neck and chest, blood tests and even possible sedation for sampling the back of the throat or passing a sterile catheter down the airway to wash and sample what is on the lining of the airway.

While headlines can sound scary, if you dig into the stories, you will find little evidence of a deadly new illness sweeping through the dog population. For instance, that same article in Thomson Reuters quoted above states, “Testing of the mysterious respiratory illness affecting dogs across the United States has not yet revealed any new pathogens or any common cause for the wave of infections that have alarmed pet owners, the agriculture department said. Instead, common causes of canine infectious respiratory disease have been identified in many of these cases through genetic sequencing of samples, the U.S. Department of Agriculture (USDA) said in an emailed statement.”

In other words, there’s nothing new here. It is the same “common causes of canine infectious respiratory disease.”

American Kennel Club Chief Veterinarian Dr. Jerry Klein said, “I don’t think cases are as prevalent all around the country,” and, “I would advise owners not to panic when their dog coughs.”

Klein said only two dogs had been brought into his practice in Chicago with similar symptoms over the course of a few weeks, “and these cases turned out to be Bordetella,” the most common bacterial agent responsible for kennel cough in dogs.

“Part of the rising levels of panic,” said the article, “have to do with the unknown illness being called a ‘mystery illness.’” I share that view. Rumors of new illnesses can strike fear into pet owners’ hearts because they are unknown and seem threatening. My view is do not panic or isolate your pet. If your dog seems sick with sneezing or coughing, it is best to have an examination by your local veterinarian and have testing or treatments based upon their recommendations.

But probably the best way to avoid this “mysterious” illness is to turn off the television.

Dr. Ron Resnick has been in practice for more than 32 years and previously operated two veterinary hospitals. He taught at Harvard University and graduated from Tufts University, considered the best veterinary school in the world. He operates an animal hospital in Simi Valley.