A cough is a protective reflex clearing the airway. What matters is the character of the cough, what else is going on, and how long it has lasted.
Describe the cough accurately
This is the single most useful thing you can do, and it narrows the list before your vet has touched the dog.
Dry, honking, forceful, often ending with a retch and white foam — classic kennel cough, or a collapsing trachea in a small breed.
Soft, moist, “productive”-sounding, worse at night or when lying down — think heart disease or lower airway disease.
Wet and rattling, with laboured breathing and lethargy — possible pneumonia.
A goose-honk triggered by excitement or a collar, in a small breed — collapsing trachea.
Sudden onset after a walk in long grass — inhaled foreign body.
Reverse sneezing — rapid snorting inhalations with the neck extended, often alarming to watch and usually harmless. It is not a cough, and it typically stops within a minute.
Film it. Dogs rarely cough in the consulting room, and a ten-second video is worth more than any description.
Go the same day if
- Laboured or rapid breathing, or effort at rest
- Blue, grey or very pale gums — an emergency
- Coughing up blood
- Collapse or fainting
- Coughing with lethargy, fever or loss of appetite
- A brachycephalic dog with any respiratory sign
- Sudden onset after a possible inhaled object
- Worsening over hours
Book an appointment if
- The cough has lasted more than a week
- It is getting worse rather than better
- Your dog is a senior, or has known heart disease
- Exercise tolerance has dropped
- There is any weight loss
- The cough wakes them at night
The common causes
Kennel cough
Infectious respiratory disease, usually picked up where dogs congregate. Dry, honking, often dramatic — and in an otherwise well dog, usually self-limiting over one to three weeks. Rest, a harness rather than a collar, and a vet visit if the dog is unwell in themselves.
Heart disease
One of the most important causes to catch. Mitral valve disease is extremely common in small breeds; dilated cardiomyopathy in larger ones. An enlarged heart presses on the airway and fluid accumulates in the lungs.
The picture: a soft moist cough, worse at night and after lying down, with reduced exercise tolerance and sometimes an increased resting breathing rate.
Count the breaths. With your dog asleep, count chest movements for thirty seconds and double it. Consistently above about 30 breaths per minute at rest is abnormal and worth reporting. It is the single most useful home measurement in canine cardiology.
Collapsing trachea
The windpipe’s cartilage rings weaken and flatten. Common in Yorkshire Terriers, Pomeranians, Chihuahuas and other toy breeds.
Characteristic honking cough, triggered by excitement, pulling on a collar, drinking, or heat. Management includes weight loss, a harness instead of a collar, avoiding heat and excitement, and medication. Severe cases sometimes need surgery.
Lungworm
Increasingly common in some regions, spread via slugs and snails. Coughing, exercise intolerance, and in some dogs abnormal bleeding or bruising, which is the sign that most alarms vets.
It is preventable — but not every worming product covers it, so ask specifically.
Pneumonia
Wet cough, fever, lethargy, laboured breathing, loss of appetite. Can follow kennel cough, inhalation of vomit, or regurgitation in dogs with oesophageal problems. Needs prompt treatment.
Inhaled foreign body
Usually a grass seed. Sudden, persistent, often violent coughing in a previously well dog after a walk. Needs prompt investigation, because seeds migrate.
Chronic bronchitis
Long-standing cough, often in middle-aged small breeds, driven by airway inflammation. Managed rather than cured.
Laryngeal paralysis
Older large breeds, particularly Labradors. Noisy raspy breathing, a change in the bark, coughing and gagging around food and water, and heat intolerance. Can become an emergency in warm weather.
What not to do
- No human cough medicine. Many contain paracetamol, decongestants or xylitol, all dangerous to dogs
- Do not suppress a productive cough. If there is material in the lungs, coughing is doing a job
- Do not assume it is kennel cough because it sounds like it. Heart disease in an older dog is frequently mistaken for a lingering infection
- Do not use a collar on a coughing dog. Switch to a harness
What helps at home while you wait
- Rest, and restricted exercise
- A harness
- Humidity — ten minutes in a steamy bathroom
- Avoiding smoke, aerosols, strong cleaning products and dusty environments
- Keeping the dog cool
- Weight loss if the dog is overweight, which helps almost every respiratory condition
What your vet will do
History and examination first, including listening to the heart and lungs. From there, depending on the picture: chest X-rays, blood tests, a faecal test for lungworm, heart ultrasound, or airway examination and sampling under anaesthetic.
A cough lasting more than a couple of weeks generally warrants imaging rather than a second course of something empirical.
