Kennel Cough in Dogs: Causes, Symptoms and Treatment

Kennel cough — clinically known as canine infectious tracheobronchitis (CITB) — is one of the most common infectious respiratory diseases in dogs worldwide. The name "kennel cough" comes from its frequent association with places where dogs congregate in close quarters, such as boarding kennels, doggy daycare facilities, dog parks, and training classes. However, dogs can contract kennel cough anywhere they encounter other dogs, including on walks or at the groomer.

Dr. Sarah Chen, DVM: "Kennel cough is essentially the common cold of the dog world — highly contagious but usually self-limiting in healthy adults. Where it becomes concerning is in puppies, seniors, and immunocompromised dogs, where it can progress to serious pneumonia."

Kennel cough is not caused by a single pathogen but rather by a complex of bacteria and viruses that work together to overwhelm the respiratory tract's defences. The most commonly implicated agents include:

• Bordetella bronchiseptica: The primary bacterial agent, found in the vast majority of kennel cough cases. This gram-negative bacterium attaches to the cilia (tiny hair-like structures) lining the trachea and bronchi, paralysing them and triggering inflammation.
• Canine parainfluenza virus (CPIV): A highly contagious respiratory virus that damages the epithelial lining of the airways, making them vulnerable to secondary bacterial infection.
• Canine adenovirus type 2 (CAV-2): Another viral contributor that targets the respiratory epithelium.
• Canine respiratory coronavirus: Distinct from the canine enteric coronavirus, this virus contributes to the kennel cough complex in some cases.
• Mycoplasma species: Tiny bacteria-like organisms that can co-infect with other agents.

Transmission occurs through aerosolised respiratory droplets produced when an infected dog coughs, sneezes, or even barks. The pathogens can also spread through direct nose-to-nose contact and via contaminated surfaces (fomites) such as water bowls, toys, and kennel surfaces. The incubation period is typically 3–10 days, and infected dogs can shed the organisms for up to 14 weeks after clinical recovery.

The hallmark symptom of kennel cough is a distinctive, forceful cough that owners often describe as sounding like a goose honk or as though the dog has something stuck in its throat. This dry, hacking cough is typically paroxysmal — occurring in episodes — and can be triggered by excitement, exercise, pulling on a lead, or gentle pressure on the trachea (such as when you lightly press on the throat area).

Mild (Uncomplicated) Kennel Cough

In most healthy adult dogs, kennel cough presents as a mild illness with the following characteristics:

• Persistent dry, honking cough: The most prominent sign, often worse at night or after rest periods. Episodes may be followed by gagging or retching, sometimes producing white foam, which owners may mistake for vomiting.
• Normal appetite and energy: Most dogs with uncomplicated kennel cough continue to eat, drink, and behave normally between coughing episodes.
• Mild nasal discharge: Clear, watery discharge is common. Thick, coloured (yellow or green) discharge may indicate secondary bacterial infection.
• Possible sneezing: Particularly if viral agents are involved.

Severe (Complicated) Kennel Cough

In puppies, elderly dogs, brachycephalic breeds (bulldogs, pugs), and immunocompromised individuals, kennel cough can progress to a more serious illness. Warning signs that require immediate veterinary attention include:

• Productive, wet cough suggesting pneumonia
• Lethargy, loss of appetite, or depression
• Laboured or rapid breathing (respiratory rate > 40 breaths per minute at rest)
• Fever (rectal temperature above 39.5°C / 103°F)
• Thick, coloured nasal discharge
• Cyanosis (bluish tinge to gums or tongue)

If your dog is showing any of these concerning signs, don't wait — use our guide on when to worry about pet symptoms as a general framework, and contact your veterinarian promptly.

In most cases, kennel cough is diagnosed clinically — based on the characteristic cough, a history of recent exposure to other dogs, and physical examination findings. A positive "tracheal pinch test," where gentle pressure on the trachea elicits a cough, strongly supports the diagnosis.

Your veterinarian will typically perform a thorough physical examination, listening to the lungs with a stethoscope (auscultation) to check for abnormal lung sounds such as crackles or wheezes that might suggest pneumonia. In uncomplicated cases, lung sounds are usually normal or mildly harsh.

When Further Testing Is Needed

Additional diagnostics are generally reserved for severe, complicated, or non-responsive cases and may include:

• Chest X-rays (thoracic radiographs): Recommended if pneumonia is suspected. X-rays can reveal bronchial patterns, alveolar infiltrates, or lung consolidation indicating lower respiratory tract involvement.
• Complete blood count (CBC): May show elevated white blood cells (leukocytosis) if there is a significant bacterial component, or normal values in viral-predominant cases.
• Tracheal wash or bronchoalveolar lavage (BAL): Collects samples from the airways for bacterial culture and sensitivity testing. This is particularly useful for dogs not responding to initial antibiotic therapy, as it identifies the specific bacteria involved and the most effective antibiotics.
• PCR panels: Respiratory PCR panels can identify specific viral and bacterial agents involved (Bordetella, CPIV, canine influenza, canine distemper, Mycoplasma, etc.), helping to guide treatment and differentiate kennel cough from other respiratory diseases.

It is important to differentiate kennel cough from other causes of coughing in dogs, including canine influenza, heart disease, tracheal collapse (common in small breeds), allergic bronchitis, and canine distemper — a far more serious viral infection with respiratory signs that can look similar in the early stages.

Treatment for kennel cough depends on the severity of the illness. The majority of cases in healthy adult dogs resolve on their own within 1–3 weeks, but supportive care can ease symptoms and speed recovery.

Home Care for Mild Cases

• Rest: Limit exercise and excitement, which can trigger coughing episodes. Short, calm leash walks for toilet breaks are fine, but avoid vigorous play.
• Humidity: Running a humidifier near your dog's resting area, or allowing your dog in the bathroom during a steamy shower, can soothe irritated airways.
• Harness instead of collar: Switch from a neck collar to a harness to avoid putting pressure on the already-inflamed trachea.
• Honey: A teaspoon of raw honey (for dogs over 1 year) can coat and soothe the throat. This is anecdotal but widely recommended by veterinarians as a safe, gentle remedy.
• Isolation: Keep your dog away from other dogs for at least 14 days after symptoms resolve to prevent spread.

Veterinary Medical Treatment

Your veterinarian may prescribe medications depending on the severity:

• Cough suppressants (antitussives): Medications like hydrocodone or butorphanol can provide relief from persistent, non-productive coughing that disrupts sleep or eating. These are not used if a productive (wet) cough is present, as suppressing a productive cough can trap infected material in the lungs.
• Antibiotics: Doxycycline is the most commonly prescribed antibiotic for kennel cough, as it is effective against Bordetella and Mycoplasma. Courses typically last 10–14 days. Amoxicillin-clavulanate or azithromycin may be used as alternatives.
• Anti-inflammatory medications: Short courses of anti-inflammatories may be used to reduce airway inflammation in severe cases.
• Nebulisation and coupage: For dogs with pneumonia, nebulised saline can help loosen secretions, followed by gentle chest percussion (coupage) to mobilise and clear mucus.

Dogs with severe pneumonia may require hospitalisation for intravenous antibiotics, oxygen therapy, intravenous fluids, and intensive monitoring. While rare, pneumonia secondary to kennel cough can be life-threatening, particularly in very young puppies.

Prevention of kennel cough involves a combination of vaccination, good hygiene, and sensible management practices — especially for dogs that regularly interact with other dogs.

Bordetella Vaccination

The Bordetella vaccine is the primary tool for kennel cough prevention and is available in three forms:

• Intranasal vaccine: Administered as drops into the nose. Provides rapid local immunity (within 48–72 hours) and stimulates mucosal IgA antibodies directly in the respiratory tract. Many boarding facilities prefer this form due to its fast onset.
• Oral vaccine: Given as a liquid into the mouth. Similar efficacy to the intranasal form and easier to administer in fractious dogs.
• Injectable vaccine: Given as a subcutaneous injection. Takes 1–2 weeks to develop full immunity and primarily stimulates systemic (IgG) rather than mucosal immunity.

It is important to understand that the Bordetella vaccine does not prevent kennel cough entirely. Because kennel cough involves multiple pathogens, vaccination against Bordetella alone reduces severity and risk but does not eliminate it — similar to how a flu vaccine reduces but does not eliminate your risk of catching the flu. The vaccine is typically given annually or every 6 months for high-risk dogs (those frequently boarded or attending daycare).

Core Vaccines That Help

The standard core vaccine combination (DHPP/DA2PP) includes protection against canine parainfluenza virus and canine adenovirus type 2 — both contributors to the kennel cough complex. Keeping your dog up to date on preventative care and vaccinations provides a broader layer of protection.

Hygiene and Management

• Choose boarding and daycare facilities that require proof of vaccination and have good ventilation.
• Disinfect shared water bowls, toys, and bedding regularly. Bordetella is susceptible to common disinfectants (dilute bleach, quaternary ammonium compounds).
• Avoid dog parks and group settings if your dog is showing any respiratory signs.
• If your dog has been diagnosed with kennel cough, isolate from other dogs for at least 2 weeks after all symptoms have resolved.