Kennel cough is a highly contagious respiratory infection in dogs that causes a distinctive honking cough. Formally known as canine infectious respiratory disease complex (CIRDC), it’s not caused by a single germ but by a mix of bacteria and viruses that attack the airways. Most cases resolve on their own within 10 to 14 days, though some dogs develop complications that need veterinary attention.
What Causes Kennel Cough
Multiple pathogens can cause kennel cough, and dogs are often infected by two or more at the same time. The most common culprits are the bacterium Bordetella bronchiseptica and canine parainfluenza virus. Other contributors include canine adenovirus type 2, canine influenza virus (both the H3N2 and H3N8 subtypes), canine respiratory coronavirus, canine herpesvirus, and canine distemper virus. On the bacterial side, Mycoplasma species and certain Streptococcus bacteria can also play a role.
Because so many different organisms are involved, a dog can catch kennel cough more than once in its lifetime. Having recovered from one combination of pathogens doesn’t protect against a different one.
How It Spreads
Kennel cough spreads through airborne droplets when an infected dog coughs or sneezes, through direct nose-to-nose contact, and through shared surfaces like water bowls and toys. The infection thrives wherever dogs are close together: boarding facilities, dog parks, grooming salons, training classes, and shelters.
The incubation period ranges from 2 to 14 days after exposure. Some dogs can carry the infection for months without showing any symptoms, quietly spreading it to others. This is one reason outbreaks can seem to appear out of nowhere in a group of dogs that all look healthy.
Symptoms to Recognize
The hallmark sign is a forceful, dry, honking cough that sounds almost like a goose. Many owners initially think their dog has something stuck in its throat. The cough can be triggered by excitement, exercise, or light pressure on the windpipe (like pulling against a collar).
Beyond the cough, you may notice:
- Gagging or retching after coughing fits
- Runny nose or watery eyes
- Sneezing
- Lower energy than usual
- Occasional vomiting (less common)
In mild cases, dogs often remain alert and still want to eat. That’s a good sign. When a dog stops eating, becomes lethargic, develops labored breathing, or runs a fever, the infection may have progressed to pneumonia, which requires prompt veterinary care.
How Vets Diagnose It
Diagnosis is usually straightforward. A vet will listen to your dog’s history of exposure, observe the cough, and gently press on the trachea (windpipe) to see if it triggers a coughing episode. In most uncomplicated cases, that’s enough to make the call.
If symptoms are severe or don’t improve with time, vets may run additional tests. Chest X-rays can check for pneumonia. Specialized lab panels can identify which specific virus or bacterium is responsible, which helps guide treatment if the standard approach isn’t working.
Treatment and Recovery
Kennel cough is usually self-limiting, meaning it clears up on its own with rest, much like a human cold. Antibiotics aren’t needed for most cases because the infection is often viral. When there’s evidence of a secondary bacterial infection or pneumonia, a vet will prescribe antibiotics chosen based on the specific bacteria involved.
For dogs whose cough is persistent enough to disrupt sleep or cause distress, vets may prescribe a cough suppressant. These are never used when pneumonia is present, because coughing in that situation helps clear fluid from the lungs.
Severe cases, particularly in very young puppies, older dogs, or those with weakened immune systems, can require hospitalization for intravenous antibiotics, fluids, and oxygen support. This is uncommon but worth knowing about.
What You Can Do at Home
Most of your dog’s recovery will happen at home, and a few simple adjustments make a real difference. Switch from a collar to a harness for walks. Collars put pressure directly on the throat, which triggers coughing fits. A harness distributes that pressure across the chest and shoulders instead.
Humidity helps soothe irritated airways. Run a hot shower and let your dog sit in the steam-filled bathroom for 10 to 15 minutes. You can do this a couple of times a day. Keep your dog in a calm, low-stress environment, and avoid vigorous exercise until the cough has fully resolved. Limit contact with other dogs during this time to prevent spreading the infection.
Vaccination Options
Vaccines for Bordetella bronchiseptica, the most common bacterial cause, come in three forms: intranasal (squirted into the nose), oral (given by mouth), and injectable. The intranasal and oral versions need only a single dose and can be given to puppies as young as 3 weeks old, depending on the product. Injectable versions require two doses spaced 2 to 4 weeks apart. All types call for annual boosters.
One important detail: the intranasal and oral vaccines are live vaccines and must never be accidentally injected. Likewise, the injectable version won’t work if given intranasally or orally. Your vet will know which form they carry and how to administer it properly.
The Bordetella vaccine is considered a “lifestyle” vaccine, recommended for dogs that regularly interact with other dogs. Boarding facilities, daycares, and groomers typically require it. Keep in mind that because kennel cough involves many different pathogens, vaccination significantly reduces risk but doesn’t eliminate it entirely. A vaccinated dog can still catch kennel cough from a virus not covered by the vaccine, though the illness tends to be milder.
Atypical Respiratory Outbreaks
Veterinarians across the United States have been tracking an uptick in canine respiratory disease cases that don’t respond to standard treatment. Affected dogs experience a longer and more severe illness than typical kennel cough. Researchers at the University of New Hampshire identified a potential culprit: a non-culturable bacterium tentatively named IOLA KY405, similar to a pathogen linked to respiratory disease in humans in 2021. A definitive cause hasn’t been confirmed yet, and labs are still collecting samples from dogs in the early stages of illness to pin down what’s driving these cases.
This doesn’t change the basic care advice for most dogs with kennel cough, but it’s worth being aware of if your dog’s respiratory symptoms seem unusually persistent or severe despite treatment.