Kennel cough is a highly contagious respiratory infection in dogs that causes a persistent, forceful cough. Most cases are mild, and dogs fully recover within 7 to 10 days without needing significant medical treatment. The formal name is canine infectious respiratory disease complex (CIRDC), and it’s caused by a mix of bacteria and viruses that inflame the windpipe and upper airways.
What Causes It
Kennel cough isn’t caused by a single germ. It’s typically a combination of viral and bacterial infections working together. The most well-known culprit is a bacterium called Bordetella bronchiseptica, which colonizes the lining of the respiratory tract. Canine parainfluenza virus is another common contributor. In many cases, a virus weakens the airway defenses first, then bacteria move in and make things worse.
An infected dog sheds these organisms in respiratory secretions, which become airborne as tiny droplets. A healthy dog nearby can inhale them directly. The germs also survive on shared toys, water bowls, and other surfaces, which is why outbreaks are so common in places where dogs are close together: boarding facilities, dog parks, grooming salons, and shelters.
The incubation period ranges from 2 to 14 days, meaning your dog could pick up the infection and seem perfectly fine for up to two weeks before symptoms appear.
What It Sounds and Looks Like
The hallmark symptom is a forceful, hacking cough that sounds like your dog has something stuck in their throat. It can be dry and hoarse, or it can be wetter and followed by gagging, a swallowing motion, or the production of mucus. The cough is often triggered by excitement, exercise, or pressure on the throat from a collar.
Beyond the cough, most dogs with kennel cough appear completely healthy. They stay playful, alert, and interested in food. Some will develop a runny nose, sneezing, or mild eye discharge, but these are secondary. If your dog is bright, eating well, and acting normal aside from the coughing, you’re likely dealing with an uncomplicated case.
How Vets Diagnose It
In most straightforward cases, a veterinarian diagnoses kennel cough based on the history and a physical exam. If your dog recently spent time around other dogs and developed that characteristic honking cough, the picture is usually clear. The vet will listen to the lungs and may gently press on the windpipe to trigger the cough reflex.
When the diagnosis is less obvious, or the dog isn’t improving as expected, vets can run more specific tests. Nasal and throat swabs analyzed with PCR testing can identify the exact virus or bacterium involved. Chest X-rays help rule out pneumonia or other conditions like heart disease or airway abnormalities that can mimic kennel cough symptoms.
Treatment and Home Care
Kennel cough is often self-limiting, meaning most dogs get better on their own. Antibiotics are usually not needed unless there’s evidence that the infection has progressed to pneumonia. When a vet does prescribe antibiotics, the choice is ideally guided by testing to match the medication to the specific bacteria involved.
For dogs with a persistent cough that disrupts sleep or daily life, a vet may prescribe a cough suppressant to provide relief. These are only appropriate for uncomplicated cases. If pneumonia is present, suppressing the cough can actually be harmful because the cough is helping clear infected material from the lungs.
At home, a few simple adjustments make a real difference during recovery:
- Switch to a harness. A collar puts pressure directly on the inflamed windpipe and can trigger coughing fits. A harness distributes pressure across the chest and shoulders instead, protecting the neck.
- Add humidity. Running a humidifier near where your dog sleeps, or letting them sit in a steamy bathroom for a few minutes, can soothe irritated airways.
- Limit contact with other dogs. Your dog is contagious throughout the illness and potentially for a short period after symptoms resolve. Keep them away from dog parks, daycare, and boarding until they’ve fully recovered.
- Keep exercise gentle. Heavy activity and excitement can worsen coughing. Short, calm walks are fine if your dog feels up to it.
When It Becomes Serious
The main complication to watch for is pneumonia, which happens when the infection moves deeper into the lungs. Puppies, senior dogs, and dogs with weakened immune systems or pre-existing conditions are most vulnerable. Signs that the infection is worsening include labored breathing, a wet or moist-sounding cough, high fever, thick nasal discharge, loss of appetite, and noticeable lethargy. These symptoms need prompt veterinary attention because pneumonia in dogs can become severe quickly.
Vaccination and Prevention
A vaccine against Bordetella bronchiseptica is widely available and comes in three forms: an intranasal spray (squirted into the nose), an oral liquid (given by mouth), and a traditional injection. All three provide some level of protection, but the intranasal version is generally preferred. Delivering the vaccine directly to the respiratory tract stimulates a stronger local immune response compared to the oral or injectable routes.
The protection from vaccination isn’t lifelong or absolute. One key study found that clinical immunity from the Bordetella vaccine may last as little as six months, which is why many boarding facilities and groomers require proof of vaccination within the past six to twelve months. It’s also worth understanding that the vaccine doesn’t cover every pathogen involved in kennel cough. A vaccinated dog can still get sick, though the illness is typically milder.
Beyond vaccination, reducing exposure helps. If you know kennel cough is circulating at a local facility, avoid it until the outbreak clears. Good ventilation in boarding and daycare environments also lowers transmission risk.
Can Humans Catch It?
Human infections with Bordetella bronchiseptica are rare. In people with healthy immune systems, the bacterium can live harmlessly in the respiratory tract without causing problems. The risk shifts for people with weakened immune systems, including those undergoing chemotherapy, organ transplant recipients, people with uncontrolled diabetes, or anyone with significant immune suppression. In these individuals, contact with an infected dog (or even a recently vaccinated dog shedding the live vaccine strain) has been linked to respiratory infections that can become serious. If someone in your household is immunocompromised and your dog develops kennel cough, limiting close contact and discussing the situation with both a vet and a physician is a reasonable precaution.