Kennel Cough in Dogs: Symptoms, Treatment & Vaccination Guide

What Is Kennel Cough?

Kennel cough, formally called canine infectious tracheobronchitis, is a highly contagious respiratory infection that causes inflammation of the trachea (windpipe) and bronchi (the airways leading to the lungs). Think of it as the canine equivalent of a bad chest cold or bronchitis in humans. The name “kennel cough” comes from the fact that the disease spreads rapidly in places where dogs congregate — boarding kennels, dog parks, grooming salons, shelters, and training classes — but your dog can catch it anywhere they encounter an infected dog.

What Causes Kennel Cough?

Kennel cough is not caused by a single pathogen. It is typically a complex of multiple infectious agents working together:

• Bordetella bronchiseptica — the most common bacterial cause and the primary target of the kennel cough vaccine. This bacterium attaches directly to the cilia (tiny hair-like structures) lining the respiratory tract, paralyzing them and preventing the normal clearance of mucus and debris.
• Canine parainfluenza virus (CPIV) — a highly contagious respiratory virus that damages the lining of the airways. It is included in most combination vaccines (DHPP).
• Canine adenovirus type 2 (CAV-2) — another respiratory virus included in core vaccines that can contribute to the kennel cough complex.
• Canine respiratory coronavirus (CRCoV) — not to be confused with COVID-19, this is a species-specific virus that contributes to respiratory disease in dogs.
• Mycoplasma species — bacteria-like organisms that can cause or worsen respiratory infections.
• Canine influenza virus (H3N2 and H3N8) — while technically a separate disease, canine flu can present similarly and sometimes co-occurs with kennel cough.

In most cases, a viral infection weakens the respiratory defenses first, and then Bordetella takes hold as a secondary infection. This is why many dogs develop kennel cough despite being vaccinated against one or two of the agents — the complex involves multiple pathogens.

How It Spreads

Kennel cough is extremely contagious and spreads through three primary routes:

• Airborne droplets — when an infected dog coughs, sneezes, or even barks, tiny respiratory droplets carry the pathogens up to 6 feet or more through the air.
• Direct contact — nose-to-nose greetings, shared water bowls, and mutual grooming spread the bacteria and viruses directly.
• Contaminated surfaces — the pathogens can survive on food bowls, toys, leashes, kennel surfaces, and human hands for hours to days.

An infected dog can spread kennel cough for up to 2–3 weeks after symptoms appear, and some dogs shed Bordetella bacteria for up to 3 months even after appearing fully recovered. The incubation period is typically 3–10 days after exposure.

Symptoms: The Distinctive Honking Cough

The hallmark symptom of kennel cough is a loud, forceful, dry cough that sounds like a goose honking. Many owners describe it as sounding like their dog has something stuck in their throat. The cough is often triggered by excitement, exercise, pulling on a leash, or gentle pressure on the trachea.

Other symptoms include:

• Retching or gagging at the end of a coughing fit, sometimes producing white foam
• Clear to slightly cloudy nasal discharge
• Mild sneezing
• Normal or slightly reduced appetite
• Normal energy level in mild cases — many dogs remain playful and active despite the cough

In complicated or severe cases, you may see:

• Thick, green or yellow nasal discharge (indicates secondary bacterial infection)
• Fever (above 103°F / 39.4°C)
• Lethargy and loss of appetite
• Productive wet cough (rather than dry honking)
• Difficulty breathing or rapid breathing
• In the worst cases, pneumonia can develop — a life-threatening complication

Kennel Cough vs. Other Coughs

Not every cough is kennel cough. Here is how to distinguish it from other common causes of coughing in dogs:

• Heart disease cough — typically a soft, moist cough that worsens at night or after rest, often in older dogs. May be accompanied by exercise intolerance and fluid retention.
• Collapsing trachea — also a honking cough, but chronic and recurring over months or years, most common in small breeds (Yorkies, Pomeranians, Chihuahuas). Not associated with kennel exposure.
• Allergic cough — seasonal, often with sneezing and itchy skin, not associated with fever or nasal discharge.
• Foreign body — sudden onset of gagging and coughing, often after playing with sticks or small objects. Does not respond to rest.
• Canine influenza — similar symptoms but often with higher fever (104–106°F), more severe lethargy, and potentially a longer course.

Treatment

Treatment depends on the severity of the infection:

Mild Cases (Most Common)

The majority of kennel cough cases are mild and self-limiting, resolving within 1–3 weeks without specific treatment. Your vet may recommend:

• Rest — limit exercise and excitement to reduce coughing fits
• Humidity — run a humidifier near your dog's resting area or bring them into the bathroom during a hot shower to help soothe irritated airways
• Harness instead of collar — avoid putting any pressure on the trachea
• Honey — one-half to one tablespoon of raw honey for adult dogs (not puppies under one year) can soothe the throat. This is anecdotal but widely used.
• Cough suppressants — your vet may prescribe hydrocodone or dextromethorphan-based cough suppressants for comfort, but never give over-the-counter human cough medicine without veterinary approval

Moderate to Severe Cases

If the cough is severe, the dog is very young or old, or there are signs of secondary bacterial infection, treatment typically includes:

• Antibiotics — doxycycline is the most commonly prescribed antibiotic for Bordetella. A typical course is 10–14 days. Antibiotics do not kill the viral components but address the bacterial infection.
• Anti-inflammatory medications — in some cases, a short course of steroids or NSAIDs may be used to reduce airway inflammation.
• Nebulization therapy — for dogs with significant congestion, nebulized saline or medications can help clear the airways.
• Hospitalization — dogs that develop pneumonia may require IV antibiotics, oxygen therapy, and supportive care.

Recovery Timeline

Here is what to expect during your dog's recovery:

• Days 1–3: Cough is most frequent and forceful. This is the most contagious period.
• Days 4–7: Cough frequency typically begins to decrease. Energy and appetite should remain normal in mild cases.
• Days 7–14: Most mild cases resolve. Occasional coughing may persist, especially with excitement or exercise.
• Days 14–21: Nearly all uncomplicated cases have fully resolved by three weeks.

Important: Keep your dog isolated from other dogs for at least 2 weeks after symptoms resolve, as they may still be shedding the bacteria.

When to See the Vet

While many kennel cough cases resolve on their own, seek veterinary care if:

• The cough has not improved after 5 days
• Your dog develops a fever (rectal temperature over 103°F / 39.4°C)
• Nasal discharge becomes thick, green, or yellow
• Your dog stops eating or becomes lethargic
• Breathing becomes labored, rapid, or noisy
• Your dog is a puppy under 6 months, a senior over 10 years, or immunocompromised
• Your dog has pre-existing heart or respiratory disease

The Bordetella Vaccine

The Bordetella vaccine is the primary vaccination against kennel cough and is available in three forms:

• Intranasal — delivered as drops into the nose. Provides the fastest protection (within 48–72 hours) because it stimulates local immunity right at the site of infection. Most commonly used.
• Oral — given as drops into the mouth. Similar speed of protection to intranasal, with the advantage of being easier to administer for dogs that resist nasal drops.
• Injectable — given as a subcutaneous injection. Takes longer to provide protection (about 1–2 weeks) and may not provide as strong local respiratory immunity, but avoids the mild sneezing some dogs experience after intranasal vaccination.

Vaccination schedule: Puppies can receive their first Bordetella vaccine as early as 6–8 weeks of age, with a booster 2–4 weeks later. Adult dogs typically receive a booster every 6–12 months, depending on risk level. Dogs that frequently board, attend daycare, go to dog parks, or visit groomers should be vaccinated every 6 months.

Important limitation: The Bordetella vaccine does not guarantee your dog will not get kennel cough. Because the disease involves multiple pathogens, a vaccinated dog can still become infected by a different agent in the complex. However, vaccinated dogs typically experience milder symptoms and faster recovery than unvaccinated dogs.

Prevention

• Keep vaccinations current — ensure your dog's Bordetella and DHPP vaccines are up to date, especially before boarding or group activities.
• Avoid exposure during outbreaks — if you hear of kennel cough cases at your dog park or boarding facility, stay away until the outbreak is contained.
• Choose reputable facilities — boarding kennels and daycares should require proof of Bordetella vaccination, maintain proper ventilation, and sanitize regularly.
• Bring your own bowls — avoid communal water bowls at dog parks and events.
• Isolate sick dogs — if one dog in a multi-dog household develops kennel cough, isolate them immediately. Other dogs in the home have likely already been exposed, but isolation reduces the viral/bacterial load.
• Support immune health — a healthy diet, regular exercise, adequate rest, and minimal chronic stress help your dog's immune system fight off infections.

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