Dog Coughing: Causes, When to Worry and What to Do

What it usually means

A cough is a reflex that clears the airways, and it can come from the throat, windpipe, lungs or even the heart. That is why coughing is a symptom, not a diagnosis. Fluid backing up from heart failure, for example, can cause coughing and labored breathing even though the problem is not in the lungs themselves.

The sound gives vets clues. A deep, honking cough points to the upper airway. A wet, phlegmy cough suggests mucus in the lungs and lower airways. A deep, dry cough can be linked to allergies, and if it persists it may be chronic bronchitis. A high-pitched gag can mean something is lodged in the throat.

Kennel cough is the best known cause. It inflames the upper airways and causes harsh, dry coughing fits, sometimes ending in retching. It spreads quickly where dogs mix, such as kennels, daycare and vet clinics. Most dogs have few other signs, but puppies can develop pneumonia, so watch for fever, a wet cough or tiredness. Other causes include heartworm and heart disease. Our page on kennel cough has more detail.

Common causes

Cause	What it means	Urgency
Kennel cough	A highly contagious airway infection with harsh, dry coughing fits, sometimes followed by gagging. Puppies are most at risk of complications.	Call your vet
Irritated airways	Dust, smoke, allergens or an irritated throat can trigger coughing.	Often minor
Something stuck or inhaled	A foreign object or choking, often with a high-pitched gag. Needs immediate care.	See a vet now
Collapsing trachea	Softened windpipe rings cause a honking cough, often set off by excitement or pulling on a collar. Seen especially in toy breeds.	Call your vet
Heart disease	Fluid in the lungs can cause a soft cough when lying down or at night, with less stamina and faster resting breathing.	See a vet now
Pneumonia	Usually a wet, phlegmy cough. Most common in young puppies and seniors, and can cause breathing trouble.	See a vet now
Heartworm disease	A mosquito-borne parasite that starts with a mild cough and can progress to a persistent cough and exercise problems.	Call your vet
Canine influenza	A contagious respiratory virus. The cough can last up to a month.	Call your vet
Chronic bronchitis	A deep, dry cough that persists for months. It can be linked to allergies or long-term airway irritation.	Call your vet
Less common serious causes	Distemper, lung tumors and other cancers can also cause a cough.	Call your vet

What you can do at home

A single dry cough, or a short bout after water goes down the wrong way, can usually be watched at home. Keep notes on how often your dog coughs, what the cough sounds like, and whether it is worse at night, after exercise or when excited. A short video helps your vet.

If your dog seems to have kennel cough, keep them away from other dogs and call your vet before visiting, so the clinic can protect other patients. Check other dogs in the household.

Keep your dog calm and resting, since activity can worsen coughing. Avoid pressure on the neck by using a harness instead of a collar. A humidifier without essential oils or fragrances can soothe the airways, and keep your dog away from smoke, dust and strong sprays.

If your dog has heart disease, your vet may ask you to count breaths while your dog is sleeping or resting quietly. Report a clear rise to your vet.

Do not give human cough or cold medicines, or leftover pet medicine, unless your vet says so. If your dog is struggling to breathe, do not wait. Go to an emergency vet.

What happens at the vet

Your vet will ask how long the cough has lasted, what it sounds like, whether it is worse at night or with exercise, and about vaccines, heartworm prevention and contact with other dogs. They will examine the nose, throat, chest and heart.

Tests depend on the suspected cause. Chest X-rays are common for lung and heart problems, and neck X-rays can show the windpipe. Other options include blood tests, measuring blood oxygen, looking into the airways with a small camera, collecting samples from the airways for culture, and ultrasound.

Treatment follows the cause. Uncomplicated kennel cough often resolves with rest and good care, and some dogs get cough suppressants or antibiotics. Bacterial infections are treated with antibiotics, fluid on the lungs with medicine to remove it, and low oxygen with oxygen therapy. Dogs with canine influenza usually need medication from your vet. A collapsing trachea has several treatment options, and surgery is sometimes recommended. Heartworm treatment is lengthy and involves strict activity restriction. Your vet will explain what to expect for your dog.

Prevention

Vaccines protect against several causes of kennel cough, including distemper, parainfluenza, canine adenovirus-2 and Bordetella bronchiseptica. A canine flu vaccine is offered by some vets. Ask your vet which vaccines and schedule suit your dog, especially if you board, use daycare or visit dog parks.

Use heartworm prevention year-round, as your vet advises. Treatment is lengthy and restrictive, so prevention is far easier.

Good conditions matter too. Reduce stress, avoid mixing animals from many different sources, and keep living spaces free of drafts, damp, dust and poor ventilation. Avoid sudden diet changes. Keep your dog away from cigarette smoke and other airway irritants.

If your dog has a collapsing trachea, ask your vet whether a harness is better than a collar, since pulling on a collar can set off coughing, and avoid exercise in hot, humid weather.

Frequently asked questions

What does a honking cough mean in a dog?

A deep, honking cough points to the upper airway. Kennel cough is a common cause, and a collapsing trachea is another, especially in toy breeds such as Yorkshire Terriers, Pomeranians and Shih Tzus. See your vet to find out which it is.

How long does kennel cough last, and is it contagious?

Kennel cough is highly contagious between dogs. The cough usually starts to ease within the first five days or so, but the illness typically lasts 10 to 20 days. Call your vet if there is fever, nasal discharge, a wet cough or tiredness, since those suggest a complication.

Why does my dog cough at night?

A soft, continuing cough when lying down or at night, with less stamina during the day, can be a sign of heart disease. Tell your vet, especially if your dog's resting breathing seems faster than usual.

Is it normal for a dog to cough after drinking water?

A brief cough when water goes down the wrong way is usually harmless. If it happens often, or comes with other signs such as tiredness or poor appetite, have your vet take a look.

Written from veterinary sources by the Pawsplained editorial team. Not yet reviewed by a veterinarian; this is general information, not a diagnosis or treatment plan. Updated Oct 30, 2026. Editorial policy