A mystery illness sickening dogs in at least 14 states in the U.S. is concerning veterinarians, as some dogs have died from the disease and the holiday season may increase dogs' risk for contracting it.
Since early November, multiple groups, including the Colorado and Oregon departments of agriculture and the American Veterinary Medical Association (AVMA), have issued warnings about the mystery illness in dogs, the cause of which has yet to be identified.
The illness is likely either due to a bacteria or a virus, experts tell TODAY.com, but it doesn't respond well, or at all, to standard treatments, such as antibiotics. The typical first symptom is a cough, which may last for weeks or even months. In some dogs, the cough turns into pneumonia, causing them to struggle to breathe.
"It seems to happen very, very quickly — to go from this cough that’s just won’t go away ... and then all of a sudden they develop this pneumonia," Dr. Lindsey Ganzer, veterinarian and CEO at North Springs Veterinary Referral Center in Colorado Springs, Colorado, tells TODAY.com.
It's unclear how many dogs have developed the illness, as most states are not formally tracking cases. However, anecdotally, veterinarians in critical care settings tell TODAY.com that they've seen dozens of cases since the fall, and these rates have not slowed.
Dr. Gina Kettig, veterinarian at VCA Alameda East Veterinary Hospital in Denver, said in a Nov. 20 segment on TODAY that she's seen "a plethora of these infections and it's concerning. ... We are using our isolation ward heavily with all of these infections."
Ganzer says she's seen over 30 dogs with what she believes to be the condition since October. Lately, two or three dogs a day with a mysterious cough have been coming to her hospital, and most have needed hospitalization. She's lost four dogs to the illness, but they all had severe pneumonia by the time she started treating them.
Ganzer notes that the illness seems to be affecting dogs regardless of age, size or breed, but it's most common in dogs who recently spent time with other dogs, such as at a kennel or doggy day care.
That's why many veterinarians are urging dog owners to keep their canines out of boarding facilities, groomers and anywhere else dogs tend to gather in groups for the time being.
“I think concern is fine,” Dr. Kurt Williams, director of Oregon Veterinary Diagnostics Lab, who’s been researching the illness for the past month and a half, tells TODAY.com. It's not a time for dog owners to "become paralyzed with fear," he adds.
What is the mystery dog illness?
Dogs with this mystery illness usually have coughing, sneezing, eye or nose discharge, are abnormally tired, and do not test positive for any common causes of canine respiratory illness, the Oregon Department of Agriculture noted in a Nov. 9 press release.
Typically, dogs with respiratory illnesses have a cough for seven to 10 days, but some vets have seen an uptick in dogs with coughs lasting weeks to months that don't respond to treatment, the Colorado Department of Agriculture said in a Nov. 22 statement.
Dogs are most likely to contract the mystery illness by being in close contact with numerous other dogs — so places like day care, dog parks, groomers or boarding kennels, Ganzer explains.
Since mid-August, the Oregon Department of Agriculture has received reports of over 200 cases of the illness from veterinarians in the state.
An Oregon Department of Agriculture spokesperson tells TODAY.com that cases are still being reported and that the department is working with other authorities to try to find the cause of the illnesses. Veterinarians who see cases are encouraged to report them to the Oregon Department of Agriculture.
The Colorado Department of Agriculture is not currently tracking case numbers but shared that "veterinarians (in the state) are currently reporting that they are seeing double the number of cases than what is typically seen during a canine infectious respiratory disease outbreak."
Dr. Amanda Cavanagh, head of urgent care services at Colorado State University James L. Voss Veterinary Teaching Hospital, in Fort Collins, Colorado, tells TODAY.com this past summer she started seeing cases of dogs with coughs lasting several weeks or longer, and the trend has continued into the fall. She estimates her caseload of coughing dogs has doubled over the past month or so.
While dogs with a contagious cough are common in veterinary settings, Cavanagh notes that she normally sees cases decrease in the fall as temperatures drop and fewer dogs are gathering at parks. "But this year, the spike has stayed high," she explains.
In its press release, the Oregon Department of Agriculture noted that the illness can progress in three ways:
- Mild to moderate cough for six to eight weeks or longer that either doesn't respond to antibiotics or only responds a little
- Chronic pneumonia that doesn't respond to antibiotics
- Severe pneumonia that "often leads to poor outcomes in as little as 24 to 36 hours"
Cavanagh has witnessed all three scenarios play out at her hospital. Recently, she's seen more dogs than usual with a long-lasting upper respiratory infection who then develop pneumonia from a secondary bacterial infection. In a small subset of these dogs, the pneumonia can be "really severe," she explains.
Of the dogs she's treated, she says most who develop pneumonia respond to antibiotics, and many with a long-lasting cough recover with time and never get pneumonia. But of those who develop the severe pneumonia, some have died or had to be euthanized.
"That really bad pneumonia, historically, is very, very rare. Maybe I would see one case a year," Cavanagh says. "We've seen a handful of them in the past weeks to months."
How many dogs have died from the mystery illness?
Because most states are not tracking case numbers, it's not known exactly how many dogs have died from the illness.
The Oregon Department of Agriculture tells TODAY.com that it does not know how many dogs have died from the illness in the state.
However, it is confirmed that some dogs in the U.S. have died from the mystery illness.
The Colorado Department of Agriculture said in a statement that "in rare cases, the canine patients progress quickly from pneumonia to death." The Colorado State University College of Veterinary Medicine and Biological Sciences also said the illness has resulted in "some fatalities."
Ganzer estimates that five dogs at her hospital have died from the illness. Cavanagh says she's also lost some dogs to it. Williams says he was recently contacted about running tests on a dog that died from severe respiratory disease.
Possible cause of mystery dog illness identified by research lab
While this mystery dog illness is making headlines in 2023, Ganzer notes that it's been around since last year. Her hospital has been sending off samples from the dogs to University of New Hampshire’s Veterinary Diagnosis Laboratory, which has been studying the illness since 2022.
One of the biggest challenges of this mystery illness is defining what cases “fall under this umbrella of this particular entity that we’re all investigating,” Williams says. That’s because dogs can develop a cough for many reasons, and it takes time to rule out known causes.
“We’re still trying to pin down a potential cause or causes for the entity. At least in Oregon, it’s given us some some challenges,” Williams says.
Researchers at University of New Hampshire’s Veterinary Diagnosis Laboratory told NBC News that they've identified a bacterium that could be behind the surge in respiratory illness in dogs, but more testing is needed to confirm.
The bacterium is smaller than normal bacteria and hasn't been known to cause disease before, Dr. David Needle, pathology section chief at the College of Life Sciences and Agriculture at the University of New Hampshire, told NBC News. Smaller bacteria can sometimes cause worse illness because it's easier for them to bypass the dog's immune system and get into the respiratory tract and lungs, Dr. Karl Jandrey, professor at the University of California, Davis, School of Veterinary Medicine, told NBC News.
What states have the mystery dog illness?
According to a Nov. 27 statement from the AVMA, cases that match the description of the mystery dog illness have been reported, officially or anecdotally, in:
- New Hampshire
- Rhode Island
The AVMA is monitoring cases of canine respiratory illness and in contact with state officials. The association reiterated that the cause of the illness is still unknown.
In recent weeks, there have also been multiple reports of outbreaks of a deadly respiratory illness in dogs at animal shelters in the U.S. The San Diego Humane Society has lost four dogs to a "severe respiratory canine illness," according to a Nov. 15 press release.
However, the outbreak at San Diego Humane Society has been linked to two particular bacteria, Strep zoo and Mycoplasma. Dr. Zarah Hedge, chief medical officer at San Diego Humane Society, tells TODAY.com that she believes the outbreak at her shelter and others she's heard about — such as one in Las Vegas — are not related to the mystery dog illness. That's because Strep zoo and Mycoplasma are easily treatable with the right antibiotics, which saved many dogs at her shelter during the recent outbreak. Also, the sick dogs she saw didn't have a long-term cough, she says.
The AVMA also confirmed there's no indication of a connection between the outbreaks.
That said, Hedge is still concerned about the damage that severe respiratory infections, both known and unknown, can cause in dogs, especially in shelters.
"We are seeing numbers of dogs coming into shelters that we haven't seen in a very long time," Hedge says. "A lot of shelters across the country are overcrowded, and it just sets you up for disease outbreaks."
Mystery dog illness 2023 symptoms
Symptoms of the mystery dog illness include:
- Coughing that doesn't get better on its own after a week or so
- Nasal or eye discharge
- Trouble breathing, especially from the stomach
- Blue or purple gums (due to not getting enough oxygen)
"Owners should monitor their dogs closely for progressive coughing that may be accompanied by signs of ocular or nasal discharges and sneezing," the AVMA said in a statement.
"Please consult your veterinarian immediately if those clinical signs develop, particularly if your dog concurrently loses its appetite, has trouble breathing, is coughing continually, or is extremely lethargic."
Ganzer stresses that any dog owners who notice their dog coughing, especially if they recently spent time with lots of other dogs, such as at a day care, kennel or dog park, should be taken to the vet right away. You shouldn't wait to see if the cough clears up on its own as earlier treatment makes a big difference in recovery, she adds.
However, for many dog owners, the early signs of coughing can be difficult to recognize, Dr. Michele Forbes, Dr. Michele Forbes, owner of Compassionate Care Hospital in Ann Arbor, Michigan, says.
"Rarely do (dog owners) identify a cough until it becomes an overt problem and it’s clearly coming from the chest,” Forbes explained in a now-viral TikTok.
As a result of owners not noticing the early coughing or confusing it for something else, like throat-clearing or gagging, some dogs are arriving at vet facilities in more advanced stages of the condition, which can make it more difficult to treat, Forbes tells TODAY.com.
Some tips to help identify early signs of coughing in dogs:
- The sound dogs make when they're choking can be confused for coughing.
- Some dogs sound like they're honking kind of like a goose.
- Coughing can also sound like the dog is gagging or clearing their throat.
- The chest may heave or the abdomen may move while the dog is coughing.
- For some dogs, it looks like they're trying to cough up a hair ball and they may produce some liquid.
- A wet cough may produce a gargling sound.
- If a dog is coughing a lot, they may end up vomiting, which dog owners often confuse for a gastrointestinal issue.
- Reverse-sneezing can be confused for coughing but it's not usually a reason to call the vet unless it's paired with actual coughing, nasal discharge or any other concerning symptoms.
Tips to prevent mystery dog illness from vets
Ganzer says her No. 1 tip is to keep dogs from areas where they're likely to come into contact with other dogs (but do not delay taking your dog to the vet for needed medical care). Cavanagh advises dog owners across the country, regardless of whether they live in a state where cases have been reported, to follow this guidance.
Keeping dogs out of these situations may be difficult for many families as the holidays approach because many people rely on boarding kennels when they travel. However, Ganzer says to avoid boarding dogs over the holidays "if at all possible," adding that she's "so scared" about what may happen with the mystery illness after dogs across the country are boarded for the holidays.
"I understand that there are circumstances that are unavoidable and that some people have to (board their dogs), but I would not take this lightly," she explains. "If there's somebody that can even just come to your house and let your dog out, that's a better option."
In light of the situation, Cavanagh says she's been keeping her two dogs at home and avoiding settings where they may come in contact with other dogs. She also suggests avoiding any nose-to-nose street greetings between strange dogs.
Williams agrees that it’s “prudent” to be concerned right now about putting dogs in scenarios where they may come into contact with many other dogs. If you need to put your dog in such a situation, he suggests contacting your vet ahead of time for guidance.
To keep your dog safe and healthy overall, the AVMA recommends keeping up to date with vaccinations. "While the existing vaccines may not specifically target this unknown infection, maintaining overall health through routine vaccinations can help support a dog’s immune system in combating various infections," it said. It stresses the following vaccines: Bordetella, Adenovirus type 2, and parainfluenza combined with the injectable influenza H3N2 vaccine.
Be sure to give your dog two weeks after vaccination before interacting with other dogs so they can build up immunity.
If your dog is sick, consult a vet right away, as early testing can help with treatment, and keep the dog away from other dogs to avoid spreading the illness, the Colorado Department of Agriculture advises.
While it's unlikely a humans can get sick with the respiratory illness, because the cause is still unknown, the AVMA suggests thoroughly washing hands after handling any dogs.
If your dog has been diagnosed with the mystery coughing illness, Ganzer suggests asking your veterinarian about submitting a sample to a research lab to help with the efforts to identify the cause.
Caroline Kee contributed reporting.