Mar 17, 2024
A mystery dog illness that spread across the U.S. last
year and can lead to serious or fatal respiratory problems is still
under investigation, but cases are starting to slow, experts
say.
The illness, which started to spread more widely in the
summer and fall of 2023, causes coughing, sneezing and fatigue,
among other symptoms, and can progress quickly to pneumonia. The
dogs suspected to have it test negative for all of the typical
causes of respiratory symptoms and often don't respond to
treatment.
In a statement to TODAY.com, the American Veterinary
Medical Association says that based on "conversations with various
sources ... the number of cases are declining," adding that an "ebb
and flow" of respiratory illness in dogs over the course of the
year is common, similar to cold and flu season in humans.
The statement also explains that the U.S. Department of
Agriculture has so far not seen that the rise in respiratory
illness in dogs is linked to a new virus or bacteria.
A statement from the Animal and Plant Inspection
Service, part of the USDA, confirms to TODAY.com that the state-led
testing that the agency is helping coordinate "has not indicated
the presence of a novel pathogen or single infectious cause among
these cases."
Numerous veterinary diagnostic labs across the country
are investigating the outbreak, from Oregon to Kansas to New
Hampshire.
The APHIS spokesperson adds that the illness is not
regulated by APHIS and therefore the branch doesn't have data on
case numbers.
The Oregon Veterinary Medical Association also shared
in an Feb. 14, 2024, update that "cases seem to be waning, if not
back to normal," citing veterinarian Dr. Scott
Weese's Worms and Germs blog.
At last count, at least 19 states had reported cases of
the illness, according to various expert groups. The AVMA explained
in an earlier statement that the mystery
dog illness is difficult to track because there's no national
surveillance system.
In November 2023, veterinarians in critical care
settings told TODAY.com that they'd seen dozens of cases since the
fall.
Late last year, multiple groups — including the
Colorado and Oregon departments of agriculture, the AVMA, the Rhode
Island Department of Environmental Management and the Los Angeles
County Department of Public Health — issued warnings about the
mystery illness in dogs.
“We don’t know what is causing this situation, where
dogs are presenting at veterinarians with what private
veterinarians would call kennel cough,” Rhode Island's state
veterinarian Dr. Scott Marshall told NBC affiliate WJAR. “What’s
different about this situation is that dogs are presenting with
little bit more severe signs, not responding to usual treatments,
and unfortunately had a small number, still a number, of dogs that
have succumbed to them.”
“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, told TODAY.com. She said she treated over a
dozen dogs with what she believes is the condition between October
and November 2023.
If your dog develops a cough, do not panic, the AVMA
advises. But stay vigilant about its progression and your pet's
overall health, and contact your vet right away if anything seems
off.
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 saw 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.
One of the distinguishing characteristics of this
mystery illness outbreak was the high number of dogs who developed
pneumonia. One Colorado vet, Dr. Michael Lappin, director of the
Center for Companion Animal Studies at the Colorado State
University School of Veterinary Medicine, told NBC News the number of
canine pneumonia cases in the state rose by 50% between September
and November 2023 compared to 2022.
Marshall estimated that Rhode Island saw at least 35
cases of the mystery respiratory illness, but it's hard to know
exactly how many because not all cases are reported.
Dogs are most likely to contract it by being in close
contact with numerous other dogs — so places like doggy day
care, dog parks, groomers or boarding kennels, Ganzer said. The
illness seems to affect dogs regardless of age, size or breed,
though dogs with snort snouts, like bulldogs and pugs, may be at
higher risk.
Between mid-August and mid-November, the Oregon
Department of Agriculture received reports of over 200 cases of the
illness from veterinarians in the state but has had no additional
cases to report since.
A Dec. 1 statement from the
Washington Department of Agriculture said the state has received 16
reports of unusual canine respiratory disease. Two cases were
confirmed as such.
The Colorado Department of Agriculture also shared in
November that veterinarians in the state were seeing "double the
number of cases than what is typically seen during a canine
infectious respiratory disease outbreak."
The Wisconsin State
Journal reported that between late October and December,
clinics around the state saw six to 12 cases each, according to Dr.
Keith Poulsen, director of the Wisconsin Veterinary Diagnostic
Laboratory at University of Wisconin-Madison.
Dr. Amanda Cavanagh, head of urgent care services at
Colorado State University James L. Voss Veterinary Teaching
Hospital, in Fort Collins, Colorado, told TODAY.com that this past
summer she started seeing cases of dogs with coughs lasting several
weeks or longer, and the trend continued into the fall. She
estimated her caseload of coughing dogs doubled from October to
November.
While dogs with a contagious cough are common in
veterinary settings, Cavanagh noted 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 original 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 witnessed all three scenarios play out at her
hospital. Last fall, she said she saw more dogs than usual with a
long-lasting upper respiratory infection who then developed
pneumonia from a secondary bacterial infection.
Of the dogs she treated, she said most who developed
pneumonia responded to antibiotics, and many with the long-lasting
cough recovered with time and never got pneumonia. But of those who
developed the severe pneumonia, some died or had to be
euthanized.
"That really bad pneumonia, historically, is very, very
rare. Maybe I would see one case a year," but last fall alone,
Cavanagh saw a "handful," she said.
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." Colorado State University College of
Veterinary Medicine and Biological Sciences also said the illness
has resulted in "some fatalities."
Ganzer and Cavanagh both have had several canine
patients die from what they believe to be the condition. Rhode
Island Veterinary Medical Association President Shelly Pancoast
told WJAR that she's seen five to 10 dogs die from the mystery
illness.
“We still don’t have a great handle on how exactly we
should be treating these dogs,” Pancoast said. “A vast majority of
them are making full recovery, it’s just unlike anything we’ve seen
in previous years with kennel cough."
What states have the mystery dog illness?
According to various expert groups, cases that match
the description of the mystery dog illness have been reported,
officially or anecdotally, in:
- Colorado
- California
- Florida
- Georgia
- Idaho
- Illinois
- Indiana
- Maine
- Maryland
- Massachusetts
- New Hampshire
- Nevada
- Oregon
- Pennsylvania
- Rhode Island
- Tennessee
- Vermont
- Washington
- Wisconsin
This above list of states comes from the AVMA, the
Tennessee Veterinary Medical Association, the Louisiana State
University School of Veterinary Medicine and the Wisconsin
Veterinary Diagnostic Laboratory at University of
Wisconsin-Madison.
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
- Sneezing
- Nasal or eye discharge
- Red eyes
- Lethargy
- Trouble breathing, especially from the stomach
- Blue or purple gums (due to not getting enough oxygen)
Related: What does coughing in a
dog sound like? Vet explains in viral video
Signs of coughing in dogs
For many dog owners, the 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 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
told TODAY.com.
Some tips to help identify 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 its
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.
When to see the vet for the mystery dog
illness
Other signs that your dog should see the vet, per the
AVMA, include:
- Lingering cough
- Weakness
- Loss of appetite
- Difficulty breathing
- Worsening of illness
- Cough that is sufficiently severe that it causes the dog to
vomit or makes it hard for the animal to breathe
Tips to prevent mystery dog illness from vets
Dogs are most likely to contract the illness when in
close contact with other dogs, so previous guidance was to keep
dogs away from other dogs. But case rates have essentially returned
to normal, Weese noted in his blog.
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.
The AVMA stressed 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 as soon as possible,
as early testing can help with treatment, and keep the dog away
from other dogs to avoid spreading the illness, experts advise.
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.
Caroline Kee contributed reporting.