Why Is My Dog Coughing? Types of Cough and What They Mean

Coughing, gagging or reverse sneezing?

These are easy to mix up, and a short phone video of the episode helps your vet a great deal.

• A cough pushes air out hard through the mouth, often in a series. Many dogs retch or gag at the end of a coughing fit, so it can look as if they are trying to vomit.
• Gagging on its own, especially around eating or drinking, can point to a problem in the throat, or to something stuck there.
• Reverse sneezing is a burst of loud, snorting breaths pulled in through the nose. It sounds alarming and is often mistaken for coughing. See our guide to Reverse Sneezing in Dogs.

Your vet will want to know how long the cough has been going on, when it happens, what sets it off and whether your dog has been around other dogs recently.

Dry, honking cough

A harsh, dry cough that sounds like a goose honk usually comes from the windpipe, called the trachea, or the large airways. The two most common causes are kennel cough and a collapsing trachea.

Kennel cough, also called infectious tracheobronchitis, is caused by a mix of viruses and bacteria. These include Bordetella bronchiseptica, canine parainfluenza virus and canine adenovirus type 2. It spreads quickly where dogs mix, such as kennels, daycare and dog parks. The cough usually starts 5 to 10 days after contact with an infected dog. It comes in harsh spasms, often ending in a retch or gag, and a light touch on the throat can set it off. The cough is usually worst in the first five days, but the illness can last 10 to 20 days. Fever, low energy, a poor appetite, thick nasal discharge or a wet cough suggest a more serious infection such as pneumonia. For care and prevention, see our guide to Kennel Cough in Dogs.

A collapsing trachea is most common in toy and small breeds, such as Chihuahuas, Pomeranians, Yorkshire terriers, toy poodles and Shih Tzus. Most affected dogs are middle-aged or older. The windpipe weakens and flattens as the dog breathes, causing a dry, honking, long-lasting cough. The cough often gets worse with excitement, pressure from a collar, hot or humid weather, right after eating or drinking, and at night. Obesity, heart disease and chronic bronchitis make it worse. Weight loss, a harness instead of a collar, calm routines and a smoke-free home help many dogs, along with medicines your vet may prescribe. The condition tends to progress, and most dogs keep some cough even with treatment.

Long-lasting cough in older dogs

Chronic bronchitis means a cough that lasts at least two months with no other respiratory disease to explain it. It mostly affects middle-aged and older dogs, often small breeds. The cough is usually harsh and dry, and it can flare after sudden weather changes. Smoke, dust and other airway irritants make it worse. Because heart disease and a collapsing trachea can sound similar, a long-lasting cough always needs a proper workup.

Wet or productive cough

A moist cough, as if the dog is bringing up phlegm, often means fluid or mucus deeper in the airways or lungs. Pneumonia is an important cause. It can develop when kennel cough spreads deeper into the lungs, and it can also come with canine distemper in young or unvaccinated dogs. Fever, low energy, a poor appetite and thick nasal discharge are warning signs. A wet cough, especially in a puppy or a dog that is breathing fast, needs a vet promptly. Distemper is preventable with routine vaccination.

Heart disease and coughing

Coughing or gagging can be a sign of heart disease, especially in older dogs with a known heart murmur. As heart failure develops, fluid can leak from the blood vessels into the lungs. Other signs include fast or effortful breathing at rest or during sleep, restlessness at night or a change in sleeping position, weakness, tiring easily on walks, fainting, a swollen belly and weight loss.

The most useful home check is your dog's sleeping breathing rate. Count breaths while your dog is sound asleep in a cool room. Watch the chest rise and fall for 30 seconds, then double the number. Rates between 15 and 30 breaths per minute are normal. A rate that stays above 30 across several checks is a reason to call your vet promptly, and a high rate with other warning signs may be an emergency. Your vet can tell a heart cough from an airway cough with chest X-rays, an ultrasound of the heart and sometimes a blood test called NT-proBNP. Read more in Mitral Valve Disease in Dogs.

In areas where heartworm occurs, a mild, persistent cough is one of the early signs, along with reluctance to exercise, tiring after moderate activity, a reduced appetite and weight loss. Vets often test for heartworm in a coughing dog, even one on prevention. See Heartworm Disease in Dogs.

Lungworm

Angiostrongylus vasorum is a lungworm that dogs catch by eating infected slugs and snails, often by accident while eating grass or drinking outdoors. It has become a risk across much of the UK and is found in other parts of the world too. Signs vary and are often vague. They include coughing, fast, heavy or noisy breathing, tiring easily, weight loss, unexplained bruising or bleeding, seizures and collapse.

The bleeding problems make this parasite dangerous, so a cough together with unexplained bruising or bleeding needs a vet immediately. Diagnosis is by special stool tests or a rapid blood test. Not every dewormer covers lungworm, so ask your vet for a licensed product if it occurs where you live. Our guide to Lungworm in Dogs and Cats covers treatment and prevention.

Other causes

• Allergies and inhaled irritants, such as smoke, dust or plant fragments
• Other infections, including fungal infections
• Lung or airway tumors
• Heart enlargement in large-breed dogs with dilated cardiomyopathy

When it is an emergency

Go to your vet or an emergency clinic straight away if your dog shows any of these signs.

• Struggling to breathe, breathing fast with the mouth open, or using the belly muscles to breathe
• Blue or very pale gums or tongue
• The head and neck stretched out to get air, or noisy, wheezing or whistling breathing
• Weakness, fainting or collapse
• A cough together with unexplained bruising or bleeding
• A sleeping breathing rate that stays above 30, together with other warning signs
• Repeated retching that brings nothing up, especially with a swollen belly, which can mean bloat (GDV)

Keep your dog calm and cool on the way, and call ahead if you can. For the bloat emergency, see Bloat (GDV) in Dogs.

Book a regular appointment within a day or two if your dog is bright but the cough is getting worse, has not cleared within two to three weeks, or keeps coming back. Call sooner for puppies, older dogs and dogs with heart disease, or if the cough is wet, comes with fever, low energy or a poor appetite, or happens mainly at night or at rest.

How vets find the cause

Your vet will start with the history and an exam, listening carefully to the heart and lungs and gently feeling the throat. A cough that is easy to trigger by touching the windpipe suggests tracheitis or a collapsing trachea. Common tests include blood tests, stool tests for lungworm, a heartworm test and chest X-rays. Depending on the results, your vet may suggest an ultrasound of the heart, a camera exam of the airways called bronchoscopy, or an airway wash to look for infection.

Treatment depends on the cause. It might mean rest for kennel cough, weight loss and a harness for tracheal collapse, heart medicines for heart failure, or parasite treatment for lungworm. Do not give human cough or cold medicines unless your vet tells you to, since some human medicines are dangerous for dogs.

Care at home

• Walk your dog on a harness rather than a collar while it is coughing.
• Keep the air clean. Avoid smoking near your dog, and limit dust and strong sprays.
• Keep your dog at a healthy weight.
• Let your dog rest, and avoid hard exercise until the cough settles.
• Keep a coughing dog away from other dogs until your vet says it is no longer contagious.
• Keep vaccinations and parasite prevention up to date.

After adoption

Dogs coming from shelters, kennels and rescue settings have often been around many other dogs. Because kennel cough signs start 5 to 10 days after exposure, a cough can show up in the days after a new dog arrives home. At Paw Squadron, every dog sees a vet after rescue for a checkup, deworming and treatment against fleas and other parasites, and every dog is vaccinated before adoption. Even so, if your new dog starts coughing, keep it apart from other dogs and call your vet, especially if it is a puppy or seems unwell.

For more guides on dog health, browse PawPedia. If you adopted from us and have questions, write to us from the Contact page.