CONDITION

Kennel Cough in Dogs

Why this matters now

Kennel cough can affect dogs of any age but is most commonly encountered in settings where dogs congregate in close quarters — boarding facilities, dog parks, grooming salons, training classes, and shelters. Outbreaks tend to occur in waves, often with seasonal peaks during warmer months when social mixing increases. Puppies, elderly dogs, and those with compromised immune function may be more susceptible to developing more significant illness from the same infectious agents that produce only mild signs in healthy adult dogs.

In most healthy adult dogs, kennel cough follows a self-limiting course over one to three weeks, with the cough gradually diminishing in frequency and intensity. However, some dogs may develop secondary bacterial complications that extend the illness or deepen its effects into the lower airways. Young puppies, brachycephalic breeds, and immunocompromised dogs may experience more protracted courses or progression to pneumonia. The cough itself may persist for several weeks even after the infectious process has resolved, as the damaged airway epithelium regenerates.

Signals & patterns

Early signals

Harsh, dry cough

A distinctive forceful, dry cough that may sound like honking or goose-like is typically the first sign noticed. The cough may be easily triggered by excitement, pulling on the lead, or gentle pressure on the trachea, and often comes in paroxysms.

Retching or gagging at the end of coughing bouts

Coughing episodes frequently terminate with a retching or gagging motion that may produce small amounts of white foam or mucus. This can sometimes be mistaken for vomiting.

Clear nasal discharge

A mild, clear watery discharge from the nose may develop alongside the cough, reflecting upper airway inflammation and increased mucus production.

Normal energy and appetite initially

In uncomplicated cases, dogs often remain bright, alert, and interested in food and activity despite the persistent cough, which helps distinguish mild kennel cough from more systemic illness.

Later signals

Thick nasal discharge

If secondary bacterial infection develops, the nasal discharge may become thicker, more opaque, and yellow or green in colour, suggesting a deeper or more established infection.

Reduced energy and appetite

Progression beyond simple tracheobronchitis may be accompanied by lethargy and reduced interest in food, suggesting the infection is producing more systemic effects.

Productive or moist cough

A shift from the initial dry, honking cough to a wetter, more productive-sounding cough may indicate that the infection has extended into the lower airways or that significant secretions are accumulating.

Click to read about the biological mechanisms

How this is usually investigated

Kennel cough is often diagnosed based on clinical presentation and history of exposure, though additional diagnostics may be pursued in cases that are severe, atypical, or unresponsive to initial management.

Clinical examination and history

Purpose: The combination of a characteristic honking cough, recent exposure to other dogs (boarding, grooming, dog parks), and the pattern of onset provides the basis for a clinical diagnosis in many straightforward cases.
Considerations: Clinical diagnosis is often sufficient for uncomplicated cases in otherwise healthy adult dogs. However, other causes of coughing — including heart disease, tracheal collapse, and lower airway disease — can produce similar presentations, making careful clinical assessment important.

Thoracic radiography

Purpose: Chest X-rays help evaluate the lungs and airways, particularly when pneumonia is suspected or the cough is not following the expected trajectory for uncomplicated kennel cough.
Considerations: Radiographs may appear normal in uncomplicated upper airway infections. Changes consistent with bronchopneumonia — including increased lung density in specific patterns — may be seen when the infection has extended into the lower airways.

Respiratory pathogen testing

Purpose: PCR panels can identify the specific viral and bacterial agents involved in the respiratory infection, which may help guide targeted management and inform prognosis.
Considerations: Pathogen identification is not always necessary for clinical management of mild cases but can be valuable in outbreaks, in cases unresponsive to initial treatment, or when unusual or emerging pathogens are suspected.

Blood work

Purpose: Baseline blood tests may be helpful in assessing overall health status and identifying signs of systemic infection or inflammation, particularly in dogs that appear systemically unwell.
Considerations: Blood work is typically normal in uncomplicated kennel cough. Elevated white blood cell counts or inflammatory markers may suggest secondary bacterial infection or pneumonia.

Options & trade-offs

Management of kennel cough ranges from supportive care for mild self-limiting cases to more active intervention when complications develop or the patient is at higher risk.

Supportive care and monitoring

For uncomplicated kennel cough in otherwise healthy adult dogs, rest, humidity, avoiding irritants such as smoke and dust, and minimising collar pressure on the trachea may be sufficient while the immune system clears the infection over one to three weeks.

Trade-offs: This approach avoids unnecessary medication but requires owners to monitor for signs of progression. The persistent cough can be distressing to observe, and there is a small risk that uncomplicated cases may develop secondary complications.

Antimicrobial therapy

Antibiotics targeting Bordetella bronchiseptica and other bacterial components may be used when bacterial involvement is suspected or confirmed, when the nasal discharge becomes purulent, or when the patient is at higher risk of complications.

Trade-offs: Antimicrobials may shorten the course of bacterial infection but do not address viral components of the disease complex. Their use in mild, self-limiting cases contributes to antimicrobial resistance concerns, making case selection important.

Cough suppressants

Antitussive medications may be considered to reduce the frequency and severity of coughing episodes, particularly when the cough is interfering with rest, eating, or sleeping.

Trade-offs: Cough suppression can improve comfort but may be counterproductive if there is a productive component to the cough where clearing secretions is beneficial. They are generally avoided if pneumonia is suspected, as coughing helps clear infected material from the lower airways.

Vaccination

Preventive vaccination against Bordetella bronchiseptica and canine parainfluenza virus is available in injectable, intranasal, and oral formulations. Vaccination may reduce the severity of illness rather than completely preventing infection.

Trade-offs: Vaccination does not protect against all pathogens in the kennel cough complex, and breakthrough infections can occur. However, vaccinated dogs tend to experience milder and shorter courses of illness. The timing of vaccination relative to exposure affects its protective value.

Common misconceptions

Misconception:

"Kennel cough only occurs in kennels"

Reality:

Despite its name, kennel cough can be acquired wherever dogs come into close contact with each other — including dog parks, grooming salons, veterinary waiting rooms, training classes, and neighbourhood walks. Any environment where respiratory droplets can be shared between dogs presents a potential transmission opportunity.

Misconception:

"Vaccination completely prevents kennel cough"

Reality:

Available vaccines target specific pathogens within the kennel cough complex, primarily Bordetella bronchiseptica and canine parainfluenza virus. Since multiple different organisms can cause similar clinical signs, vaccinated dogs may still develop respiratory infections from agents not covered by the vaccine. Vaccination tends to reduce the severity and duration of illness rather than providing complete protection.

Misconception:

"A coughing dog always needs antibiotics"

Reality:

Many cases of kennel cough are caused by viral agents against which antibiotics are ineffective. In uncomplicated cases affecting otherwise healthy adult dogs, the infection is often self-limiting and resolves with supportive care alone. Antimicrobial therapy is most appropriate when there is evidence of bacterial involvement, secondary complications, or the patient is at higher risk.

Isolating a coughing dog from other dogs during the infectious period — typically for two to three weeks after the cough begins — helps reduce transmission to other animals. Using a harness rather than a collar avoids putting pressure on the inflamed trachea that can trigger coughing bouts. Maintaining a calm environment with adequate humidity and minimal exposure to irritants supports recovery. Monitoring for signs that the illness may be progressing beyond uncomplicated upper airway infection — such as developing lethargy, appetite loss, laboured breathing, or persistent fever — helps identify cases that may benefit from more active management.

Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS