What Is Kennel Cough?
Kennel cough is the common name for infectious tracheobronchitis, an umbrella term for a collection of contagious respiratory infections in dogs. The characteristic sound — a harsh, honking cough that can seem alarming the first time you hear it — is caused by inflammation of the trachea and bronchi. Despite the name, dogs do not need to visit a kennel to contract it. Any situation where dogs are in close proximity creates ideal conditions for spread.
The infection is usually caused by a combination of agents rather than a single pathogen. Bordetella bronchiseptica is the most commonly implicated bacterium, but canine parainfluenza virus, canine adenovirus type 2, canine coronavirus, and mycoplasma species are frequently involved as co-pathogens. This is why even vaccinated dogs can occasionally develop kennel cough — the vaccine covers the major culprits but not every possible contributor.
How It Spreads
Kennel cough spreads with remarkable ease. The bacteria and viruses involved are transmitted through airborne droplets from coughing and sneezing, through direct contact with an infected dog, and through contact with contaminated surfaces like water bowls, leads, and fencing. Incubation typically runs between two and fourteen days, meaning a dog can be infectious before showing any signs at all.
High-risk environments include boarding kennels, dog day care centres, dog parks, training classes, and grooming parlours. Any space where multiple dogs share air or surfaces carries some level of transmission risk. This is not a reason to avoid socialisation — it is a reason to keep vaccinations current and stay alert to symptoms after any group dog activity.
Recognising the Symptoms
The defining sign is the cough itself. It tends to be forceful, persistent, and often ends with a retching or gagging motion that owners sometimes mistake for the dog trying to vomit. Some dogs gag up a small amount of white foam after coughing fits, which adds to the concern. Additional symptoms may include:
- A runny nose with clear discharge
- Eye discharge
- Sneezing
- Mild lethargy
- Reduced appetite
In uncomplicated cases, dogs usually remain bright, alert, and interested in food and activity despite the coughing. A dog that is eating, drinking, and behaving normally between coughing fits is a very different clinical picture from a dog that is lethargic, febrile, and refusing food.
When Kennel Cough Resolves on Its Own
In healthy adult dogs with no underlying health conditions, uncomplicated kennel cough typically resolves without treatment within one to three weeks. The immune system, assuming it is functioning normally, clears the infection in a similar timeframe to a human cold. During this period, rest, reduced exercise to avoid triggering coughing fits, and access to fresh water are the main management strategies.
Some vets recommend honey in small quantities to soothe the throat, though evidence for this is anecdotal. Avoiding environments with smoke, dust, or strong chemical smells reduces airway irritation. A harness rather than a collar during recovery can also help, as pressure on the trachea from a collar can provoke coughing.
Dogs should be kept away from other dogs until they have been symptom-free for at least two weeks, as they can remain contagious even as they improve.
When Veterinary Attention Is Needed
Kennel cough becomes a more serious concern in specific circumstances. Do not take a wait-and-see approach if any of the following apply:
- The dog is a puppy, senior, or has a pre-existing health condition
- Symptoms have not improved after ten to fourteen days
- The dog develops a high fever
- Lethargy is marked and persistent, not just mild tiredness
- Breathing becomes laboured, rapid, or noisy
- The dog stops eating or drinking
- Nasal or eye discharge turns thick and yellow-green
These signs suggest the infection may have progressed to pneumonia, which requires prompt veterinary treatment. Kennel cough pneumonia is not common, but it is a genuine risk in vulnerable dogs. Bordetella bronchiseptica is particularly capable of colonising the lungs in immunocompromised animals.
Brachycephalic breeds — Bulldogs, Pugs, French Bulldogs, and similar — warrant earlier veterinary assessment because their narrowed airways make respiratory compromise more likely and harder to spot before it becomes dangerous.
Antibiotics and Other Treatments
Whether to prescribe antibiotics for kennel cough is a nuanced decision. Because the infection is often viral in origin or mixed, antibiotics will not always shorten the course of illness. Many vets take a conservative approach in healthy adult dogs with mild symptoms, opting to monitor rather than prescribe immediately.
Antibiotics are typically prescribed when the dog shows signs of bacterial involvement or secondary infection — thick purulent discharge, high fever, signs of pneumonia — or when the patient is in a higher-risk category such as a puppy or senior dog. Doxycycline is commonly used as it covers Bordetella effectively.
Cough suppressants are sometimes prescribed for dogs with severe or sleep-disrupting coughs, though they are used with caution as suppressing the cough reflex can occasionally allow mucus to build up in the airways.
Vaccination: What It Covers and What It Doesn't
The Bordetella vaccine is available in injectable and intranasal forms. The intranasal version is generally considered to offer faster local immunity, which is useful before planned kennel stays. Most boarding facilities and day care centres in the UK require an up-to-date Bordetella vaccination as a condition of entry.
It is worth being clear with clients and dog owners: vaccination significantly reduces the severity and likelihood of kennel cough but does not offer complete protection. The sheer number of pathogens involved makes that impossible with any current vaccine. A vaccinated dog may still develop a mild version of kennel cough, but the clinical course is typically much shorter and gentler than in an unvaccinated dog.
Annual or more frequent boosters are recommended for dogs with regular exposure through kennels, day care, or active socialisation.