Kennel Cough in Dogs: Symptoms, Home Care and When to See a Vet

What kennel cough is

Kennel cough is a very contagious infection of the windpipe and airways. Vets call it canine infectious respiratory disease complex or infectious tracheobronchitis, because it's rarely caused by a single germ: the usual culprits are the bacterium Bordetella bronchiseptica, canine parainfluenza virus and canine adenovirus type 2, often together. Canine influenza can cause a similar cough (Merck Veterinary Manual).

Your dog doesn't need to have been in a kennel. It spreads through coughing and sneezing and through shared water bowls and toys, wherever dogs get together: boarding, daycare, dog parks, grooming salons, training classes, shows and even the vet's waiting room.

Symptoms

A dry, harsh, repeated cough that sounds like honking.
Gagging or retching at the end of a coughing fit, sometimes bringing up a little white foam. Many owners think their dog is vomiting: see dog throwing up white foam.
Coughing that gets worse with exercise, excitement or pulling on the leash, because the collar presses on the windpipe.
Sometimes sneezing, a runny nose or watery eyes.

Most dogs keep eating, drinking and playing. The cough usually starts 5 to 10 days after exposure, is worst in the first 5 days and can last 10 to 20 days (Merck Veterinary Manual).

Not every cough is kennel cough

If your dog hasn't been around other dogs, the cough has lasted for weeks, or it's worse at night, something else may be going on: a collapsing trachea (common in small breeds like Yorkies and Pomeranians), chronic bronchitis, heart disease in older dogs, heartworm disease, a foxtail in the airways or pneumonia. If the cough doesn't fit the picture above, have your vet take a look. In much of the US, a cough can also be a sign of heartworm disease.

When to see a vet

Go to the vet right away if your dog:

Is breathing hard, fast or with an open mouth while resting, or has bluish or gray gums.
Coughs up blood.
Has a fever, is very lethargic or stops eating: kennel cough can turn into pneumonia.
Retches over and over without bringing anything up and has a swollen belly. That isn't a cough: it can be bloat, a life-threatening emergency.

Make an appointment in the next few days if:

The cough isn't better after a week, or it's getting worse.
There's green or yellow discharge from the nose.
Your dog is a puppy, a senior, a flat-faced breed (French bulldog, pug) or has heart or lung disease.
You're not sure it's kennel cough.

For a full list of red flags, see when to take your dog to the emergency vet.

What you can do at home

If your dog is coughing but is alert, eating and breathing normally:

Keep things calm. Short, gentle walks; no running or rough play, which triggers coughing fits.
Switch to a harness instead of a collar so nothing presses on the windpipe.
Keep your dog away from other dogs while they're coughing and for some days after: skip the dog park, daycare and boarding, and let the facility know if you had a booking. Dogs can stay contagious even as the cough fades.
Watch the air: no cigarette smoke, air fresheners or dust. Slightly humid air can help, such as sitting with your dog in a steamy bathroom.
Fresh water at all times and their usual food. If dry food is hard to swallow, moisten it.
Don't give human cough syrups or cold medicines. Some contain xylitol or ingredients that are dangerous for dogs.

What the vet will do

Kennel cough is usually diagnosed from the history and an exam: your vet will listen to the lungs, take a temperature and check whether gentle pressure on the windpipe sets off the cough. If they suspect pneumonia, or the cough won't go away, they may recommend chest X-rays (about $172 on average in the US, according to the Synchrony/CareCredit cost study) and sometimes a swab to identify the germ.

Most dogs don't need antibiotics, because the infection runs its course. Vets save them for pneumonia or complicated cases. If the cough keeps your dog from resting, your vet may prescribe a cough suppressant, but not if there's pneumonia (Merck Veterinary Manual).

Kennel cough and canine flu vaccines

These vaccines aren't required by law, but the American Animal Hospital Association (AAHA) recommends them for dogs that spend time with other dogs, such as at boarding, daycare, grooming, training or shows, and most boarding facilities and daycares ask for them (AAHA vaccination guidelines).

Bordetella: given as drops in the nose, by mouth or as an injection, and repeated every year. It costs about $39 on average in the US.
Canine influenza (H3N2/H3N8): two doses 2 to 4 weeks apart, then a yearly booster while the risk continues. About $53 per dose.

Average prices from the Synchrony/CareCredit 2025-2026 cost study. Ask your boarding facility how far in advance they need the vaccines: immunity takes some time to build.

The core DAPP vaccine already covers parainfluenza and adenovirus type 2. No vaccine prevents every case, because so many germs are involved, but vaccinated dogs tend to get milder, shorter illnesses. See the puppy vaccination schedule.

Frequently asked questions

How long does kennel cough last?

The cough is usually worst in the first 5 days and gone in 10 to 20 days. If it lasts more than three weeks or gets worse, go back to your vet.

Can a vaccinated dog get kennel cough?

Yes. The vaccines don't cover every germ that causes it, but vaccinated dogs usually have milder symptoms for a shorter time.

Can I walk my dog if they have kennel cough?

Yes, for bathroom breaks, but keep walks short, use a harness and stay away from other dogs. Avoid dog parks, daycare and boarding until your vet says your dog is no longer contagious.

Is kennel cough dangerous for puppies?

It can be more serious than in adult dogs, because it turns into pneumonia more easily. If your puppy is coughing, call your vet even if they seem fine.

Sources

This article is for general information and does not replace diagnosis or treatment by a veterinarian. If you are worried about your pet's health, call your vet clinic.