Kennel cough after boarding: why vaccinated dogs still get it, and when the cough is serious

Yes, and it is more common than kennels like to admit. The Merck Veterinary Manual puts it plainly: kennel cough has multiple causes. Bordetella bronchiseptica is the famous one, but canine parainfluenza virus, canine adenovirus type 2, canine influenza and a few less common germs cause the same cough, and dogs often carry more than one at once. Merck notes that co-infections with Bordetella, parainfluenza and adenovirus 2 are the most common pattern.

The “kennel cough shot” is a Bordetella vaccine, usually combined with parainfluenza when it is given as nose drops. It does nothing against canine influenza, which needs its own two-dose vaccine, and nothing against the viruses nobody vaccinates for. Even against Bordetella itself, the 2022 AAHA vaccination guidelines describe the evidence as showing vaccines reduce disease rather than block infection, and cite a study suggesting clinical immunity may last as little as six months. That is why AAHA suggests boosting high-risk dogs more often than yearly, for example right before boarding, and why many kennels want it within the last six months.

Form matters too. AAHA notes that injectable Bordetella vaccines have a delayed onset of immunity and stimulate little local immunity in the nose and throat, where the infection starts, so they are less effective at limiting respiratory disease than the intranasal version. A dog that got the shot the day before drop-off was barely protected at all. Our guide to dog boarding vaccine requirements covers timing before the stay; this post is about what happens after.

So the honest framing is this: the vaccine stacks the odds. A vaccinated dog that still catches kennel cough will usually have a shorter, milder case than an unvaccinated one, which is exactly what you want when the alternative is a puppy with pneumonia.

Merck says to suspect kennel cough when a cough suddenly develops 5 to 10 days after exposure to other dogs. The AKC, quoting veterinarian Randy Aronson, gives a wider range of 2 to 14 days. In practice that means a cough can start while your dog is still at the kennel, on the drive home, or up to two weeks after pickup.

The course is fairly predictable for an otherwise healthy adult dog. Merck describes the severity as usually easing over the first 5 days, with the disease persisting for 10 to 20 days. The AKC says most dogs recover within one to three weeks. The VCA puppy guide says a typical case resolves on its own over about two weeks. If your dog is still coughing hard at three weeks, or got better and then worse, that is a reason to call the vet rather than wait it out.

One thing the timeline tells you: a dog that starts honking the morning after a seven-day stay was almost certainly exposed at the kennel. A dog that starts coughing three weeks after pickup, and went to the dog park and the groomer in between, could have picked it up anywhere.

Owners usually describe it as something stuck in the throat. Merck’s description is a cough that sounds like a goose honk, often ending in retching or gagging that owners mistake for vomiting. The Merck pet-owner manual calls it spasms of harsh, dry coughing. Pressing gently on the throat or a tug on the collar will set it off, and excitement or exercise makes it worse.

Between coughing fits, an uncomplicated case looks like a normal dog. Merck notes that affected dogs usually have few other signs, with normal temperature, and most keep eating. Some sneeze or have a runny nose or watery eyes. The picture to worry about is the one where the cough comes with a sick dog.

Merck calls kennel cough a mild, self-limiting disease, but adds the two exceptions that matter: it can progress to bronchopneumonia in puppies, and to chronic bronchitis in weakened or older dogs. The pet-owner edition is blunter, saying it can progress to fatal bronchopneumonia in puppies. Puppies, senior dogs, and dogs with existing heart, airway or immune problems deserve a lower threshold for a vet visit; Merck notes that Bordetella is most likely to act on its own as a serious pathogen in dogs under six months.

For a routine case the vet visit is mostly reassurance and a listen to the chest. Merck says hospitalization is usually unnecessary and that antibiotics are usually not needed except in severe or chronic cases. Your vet may prescribe a cough suppressant to let your dog (and you) sleep, or an antibiotic if a secondary bacterial infection is suspected. Do not give human cough medicine or any leftover prescription on your own; the right call depends on the chest exam, and the wrong one can mask a chest that is getting worse.

Usually not in the way owners mean. The germs spread through coughed droplets, nose-to-nose contact and shared bowls, and Merck notes the disease spreads rapidly among susceptible dogs housed in close confinement, naming veterinary hospitals, daycare and boarding kennels. Stress and extremes of ventilation, temperature and humidity make dogs more susceptible. A kennel is, by definition, a room full of dogs from different households breathing the same air after a stressful drop-off. Some exposure risk is built into the product, which is why kennels require the vaccine in the first place.

What a good kennel can control is the size of that risk. It checks vaccine dates instead of waving dogs through. It separates a coughing dog the moment staff hear it and calls the owner. It ventilates, cleans bowls between dogs, and quarantines new arrivals from a known outbreak. The AAHA guidelines go further and say boarding kennels, along with daycares and pet stores, should consider following the same vaccination protocol as animal shelters, which means every dog gets intranasal Bordetella and parainfluenza before it enters the building.

Tell the kennel anyway. A quick call saying “Max started coughing two days after pickup, the vet thinks it’s kennel cough” is useful to them: it lets staff warn other owners from that week and look harder at their own dogs. A good operator will thank you and ask which dates your dog was in and which play group. A defensive one will tell you it’s impossible because they require the vaccine, which, as the first section shows, is not how the vaccine works. Either way, ask whether they have other reported cases; if several dogs from the same week are coughing, you want to know before you book the next stay.

The thing you can reasonably hold a kennel to is its own policy: did it actually check your dog’s records and everyone else’s? If you later learn that unvaccinated dogs were accepted, that is worth a direct conversation and a look at other boarding options nearby.

• Keep your dog home. Skip daycare, the dog park, group training and the groomer. The AKC recommends keeping a dog away from other dogs while it is coughing and for at least two weeks after the cough stops.
• Rest. Merck’s advice is rest, good food and a calm environment; the AKC suggests at least a week of reduced activity. Hard play triggers the cough and tires an already irritated airway.
• Separate dogs in the house if you can. If you have a second dog, it has probably been exposed already, but separate bowls and some distance can still reduce how much it gets. Watch it for a cough over the next two weeks.
• Swap the collar for a harness on walks if a collar sets off coughing fits, and keep walks short and slow.
• Call the vet if anything on the “call today” list appears, or if the cough is not clearly improving after about a week. Phone before you go.
• Tell the kennel and your daycare, and ask about any other reported cases.

Dogs often come home from boarding tired and a little off for a day or two even without an infection; our guide to dogs acting tired after boarding covers what is normal there. A cough is the sign that moves you from “let him sleep it off” to “keep him home and watch him.”