What All Dog Owners Need to Know About the Mystery Canine Illness

Cases of respiratory illness are being diagnosed in dogs across North America, and veterinarians aren’t sure of the cause. The Trupanion team will update this page as more information is available.

Concerns over a “mysterious” respiratory disease affecting dogs have risen in recent months as outbreaks continue across North America. But how worried should dog owners really be?

The good news is that there may not be reason for pet parents to panic just yet. Not only is research into the outbreak still ongoing, but some emerging professional opinions are that the canine illness may not be so mysterious after all. At this time, pet owners and veterinary teams alike must avoid jumping to conclusions. Here’s what we know about the mystery dog illness so far and keeping pets safe.

What is the mysterious dog illness?

It’s important that pet owners know that, despite its public moniker, the mystery illness affecting dogs is not a complete conundrum. While it has yet to be precisely defined or identified, the illness is known to be respiratory in nature, has a range of identified symptoms, and it may in fact already be a recognized or even a common health condition. Veterinary teams are simply still working to determine the viral or bacterial cause of the disease as well as the exact prevalence — hence the "mysterious" and “unknown” labels. In the meantime, some health organizations are using the term Atypical Canine Infectious Respiratory Disease Complex, or aCIRDC as a more official name for the illness.

Some cases have been reported as progressing to pneumonia, while others have been reported as not responding to typical treatments known to work with illnesses like kennel cough and canine influenza. Though the illness has been hyped in some circles as fatal, this is from cases leading to pneumonia (mortality as a direct result of the mystery illness has not been confirmed).

What veterinarians say

In a recent webinar hosted by Trupanion, Dr. Scott Weese from the Ontario Veterinary College suggested the mystery dog illness might not actually be a new thing but rather a more prevalent occurrence of common canine respiratory infections. As Weese pointed out, the COVID pandemic of the past few years resulted in more dogs and busier veterinary practices, along with changes in social standards that could have all contributed to less vaccination in pets as well as less routine public exposure.

“So what the net result could be is we have more dogs that have a lower level of resistance because they’ve been exposed less over the last couple of years, and they’ve had less vaccination,” Weese said in the panel. “So that means just with our normal respiratory disease that’s always there, always circulating around, we can see more disease and more spikes.”

In the same webinar discussion, Dr. Michael Lappin of the Colorado State University College of Veterinary Medicine noted that his school has seen a 50% increase in canine pneumonia cases in 2023 compared to the previous year.

While Lappin agreed with Weese that the outbreak could just be greater awareness of canine health and extenuating factors of recent years, he noted that he would like to see the vaccination history for the dogs getting sick and looks forward to what the coming weeks and months of research into the illness will reveal. Both veterinarians said that while the mystery illness could be either viral or bacterial in nature, it’s a good idea for pet owners to stay current on their dogs’ vaccinations.

Claims data may hold the key

What’s currently being referred to as the mystery canine illness was first noticed in summer 2023 and has increased in prevalence and affected regions over the past few months.

Exact prevalence is unknown, though this is largely due to variations in veterinary data collection and reporting across regions and practices. Trupanion claims data meanwhile shows an increase in pet insurance claims for canine respiratory illnesses between August and October 2023, compared to 2022 in certain parts of North America:

• Quebec, Canada - 70.73% increase
• Ontario, Canada - 25.17% increase
• California, US - 8.71% increase
• Colorado, US - 36.46% increase
• Oregon, US - 61.86% increase
• Nevada, US - 43.05% increase

Significant changes have not been noted (so far) in other areas, but this could also be due to cases of the mysterious canine illness being reported as different types of claims. Many dogs are also not insured.

Important FAQs for dog owners

As information unfolds about the mysterious canine health condition, it’s wise for pet owners to err on the side of caution even if there turns out to not be much cause for alarm. This includes becoming more informed about respiratory illnesses in dogs and taking steps toward prevention of sickness in general.

What are the clinical signs of the mystery dog illness?

Symptoms of the so-called mysterious canine illness vary from dog to dog but are overall similar to those of severe colds and respiratory infections. Pet owners should be on the lookout for the following signs:

• Intense coughing (often lasting for weeks)
• Runny eyes
• Nasal discharge
• Loss of appetite
• Frequent sneezing
• Lethargy
• Fever

Because there’s the likelihood of the mysterious canine illness being a cluster of conditions rather than one specific disease, there may be further variation in symptoms between individual dogs.

Is the mysterious canine illness fatal?

Though not much is yet known about the mystery dog illness, some cases have been reported to progress quickly and be fatal in under 48 hours. However, this quick progression has been observed in cases where dogs were already showing signs (like coughing) for weeks and/or may have had an underlying condition that negatively affected their health overall.

Where are sick dogs being reported?

According to the American Veterinary Medical Association (AVMA), reports of an unknown canine infectious respiratory illness began popping up in the Portland metro and Willamette Valley areas of Oregon in August, rising to over 200 cases by mid-November. As of December 2023, cases of the mysterious dog disease have been reported in Canada as well as the following US states:

• California
• Colorado
• Florida
• Georgia
• Idaho
• Illinois
• Indiana
• Maine
• Maryland
• Massachusetts
• New Hampshire
• Nevada
• Oregon
• Pennsylvania
• Rhode Island
• Tennessee
• Vermont
• Washington
• Wisconsin

Lack of research funding and centralized reporting on dog illness outbreaks makes it challenging to track the exact transmission, fatality, and prevalence numbers. Pet owners who do not live in the above listed states or Canada are advised to stay aware of the ongoing outbreaks. Like many canine health conditions, one possible cause of this particular illness is a virus that could spread to additional areas.

Can humans catch the mysterious canine illness from dogs?

While it’s not unheard of for dogs to transmit illnesses to humans, most experts who’ve spoken on the matter agree that the mysterious canine respiratory condition is not likely a risk to people.

“In general, the risk of people getting sick from dogs with canine infectious respiratory disease is extremely low,” Dr. Rena Carlson of the AVMA said in a statement on November 29 . “However, because we don’t know yet exactly what agent or agents ... are causing the current outbreak, it’s a good idea to thoroughly wash your hands after handling your or other dogs.”

How to prevent your dog from getting sick

As the cause of the illness is not yet known to be viral or bacterial, it’s best to take caution in both areas. Due to their naturally curious nature, dogs can easily put themselves at risk in any setting. Pet owners should be especially vigilant at this time to prevent viral and bacterial infections from affecting their furry companions:

• Ensure your dog’s vaccinations are up to date.
• Keep dogs away from large group gatherings and public settings with people and other dogs.
• Take a break from the dog park and other non-essential social outings with your pet.
• Don’t allow pets to drink out of public water sources (especially dog bowls). Likewise, avoid dirty-looking water or still, standing water.
• Wipe off dog paws whenever coming in from being outdoors.
• Avoid sick dogs, especially those showing signs of respiratory illness.
• If using a kennel or dog grooming service, ask about their health safety measures and vaccination requirements.
• Call your veterinarian (don’t show up in person before doing so) if you notice signs of respiratory illness in your own pet.

Canine health is often unpredictable in general. Pet owners who have not yet explored dog insurance options may want to consider doing so to protect against unexpected, surprise illnesses.