Everything You Need to Know About Dog Flu, According to Veterinarians

Including the new mystery disease going around

everything you need to know about dog flu
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Getting the flu is no walk in the (dog) park, especially for pups who probably don’t understand what’s happening to them. Canine Influenza Virus (CIV) is a relatively new discovery in the disease world, but it’s gaining momentum and hitching rides overseas as eagerly as college kids ready to study abroad. Here’s everything you need to know about dog flu, including some important info on the mystery canine respiratory disease currently affecting dogs all over the country, to protect the pup in your life.

Meet the Experts

  • Dr. Zac Pilossoph is a consulting veterinarian at Healthy Paws Pet Insurance. He has spent years traveling the country, working with pets and pet parents to find holistic solutions to animal ailments. Dr. Pilossoph’s areas of expertise include medical cannabis and CBD products for pets and immune-mediated diseases, just to name a few.  
  • Dr. Kristine Smith is the Biologicals and Infectious Disease Medical Lead at Zoetis, a pet wellness company dedicated to researching animal health and developing the best products and processes to keep pets healthy and happy. She is board-certified in zoological medicine and has two decades of experience working with infectious diseases in animals.
  • Dr. Karen Stasiak is the Head of Core Dx and Infectious Disease Platforms with the Global Diagnostic team at Zoetis. She owned her own veterinary practice for 13 years before joining Zoetis, so she’s seen it all. 
  • Dr. Mondrian Contreras, DVM, is a Member of the Pumpkin Veterinary Advisory Board. He also owns and operates a vet clinic and doggy day care business. He’s on a mission to make sure pets and the people they love are taken care of. 
  • Dr. Danielle Bernal is a global veterinarian with Wellness Pet Company and all about natural wellness to ensure long, healthy pet lives.
Woodbury, Minnesota, Animal humane society closed due to canine influenza. Canine influenza is a contagious respiratory disease in dogs caused by specific Type A influenza viruses known to infect dogs.
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What Is Dog Flu?

According to the American Veterinary Medical Association, CIV is a respiratory disease caused by two separate Type A viruses. (Type A means the virus can infect animals, and its strains are always changing.) The first virus, CIV H3N8, showed up in Florida in 2004. The other, CIV H3N2, was discovered in Asia in 2006. Merck Animal Hospital says that in 2007 in the U.S., only Florida and Tennessee reported cases of H3N8 in dogs. By 2014, 36 states confirmed infection from H3N8. The next year, Chicago experienced a huge outbreak of H3N2, the first time this strain was reported in the U.S. Since 2018, 46 states have claimed cases of one or both strains.

Basically, CIV, or dog flu, is on the move.

everything you need to know about dog flu vet exam
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What Are the Signs and Symptoms of Dog Flu?

Dr. Karen Stasiak, a veterinarian at the animal health care company Zoetis, says appetite loss, cough, lethargy and a runny nose can all indicate a dog flu infection. These symptoms can last for a few weeks and change depending on the strain. “As with flu in humans, symptoms and severity of infection may vary from dog to dog,” she adds.

Other possible symptoms of dog flu include sneezing, watery eyes and labored breathing, according to Dr. Zac Pilossoph, a consulting veterinarian at Healthy Paws Pet Insurance.

Dr. Mondrian Contreras, DVM, a member of the Pumpkin Veterinary Advisory Board, says it’s common for pet owners to mistake CIV for kennel cough, but dogs with the flu have more intense symptoms. It’s also worth noting symptoms of H3N8 are less intense than those of H3N2. Keep an eye on your pup and visit the vet even if a cough seems mild or a runny nose isn’t super detrimental to your dog’s energy levels. You don’t want mild symptoms to become more severe over time.

How Does Dog Flu Spread?

Dog flu can spread quickly. First of all, CIV is not seasonal (aka, your dog can contract it at any time, not just during a polar vortex). All it takes is a sneeze, cough or lick to share germs and transfer CIV. Romps in the dog park, stays at a kennel and sharing toys can all lead to spreading dog flu.

While the Centers for Disease Control and Prevention reports there are no known cases of humans contracting either strain of CIV, in 2016 UW-Madison's School of Veterinary Medicine reported a group of cats in an Indiana shelter contracted H3N2 after contact with infected dogs. This means dog flu can spread to other pets in the house, which could be a pretty miserable situation.

How Severe Is Dog Flu?

Let’s cut to the chase: Can dog flu kill my dog? This is a tough question because it depends on the dog. After two to three weeks, most pups are back to their usual selves. Just like when you get the flu, your body fights it off as best it can and eventually you get better.

Dr. Pilossoph doesn’t want dog parents to freak out if their pup displays flu-like symptoms. He says dog flu isn’t actually very common, at least not like the human flu season where it’s inevitable that you’ll get a bug at some point. Dr. Pilossoph says the number of dogs who get super sick or die from dog flu is extremely low.

However, Dr. Stasiak says canines who are very young, very old or have compromised immune systems are at risk of developing pneumonia as a result of CIV, which can be fatal if left untreated.

In fact, a new canine respiratory disease spread across the U.S. this fall, causing pneumonia in all types of dogs. Some died, while others remained sick for weeks. Many vet clinics are seeing shockingly high rates of dogs with pneumonia or breathing issues, yet scientists aren’t sure what’s causing it or how widespread the infection actually is.  

According to Dr. Contreras, this mystery illness starts with similar symptoms to dog flu, like coughing, then progresses to fever, sneezing, runny nose and watery eyes. Though similar to CIV, Dr. Contreras says this new disease causes symptoms for a longer period of time. The illness is also more resistant to antibiotics.

Dr. Kristine Smith, the Biologicals and Infectious Disease Medical Lead at Zoetis, advises keeping up to date on any news of canine respiratory outbreaks in your area so you don’t accidentally let your dog loose in a dog park full of super-spreaders.

How to Treat Dog Flu

Unfortunately, Dr. Pilossophh says there is no medication that cures CIV because it’s a virus. Like something out of Outbreak, the viruses are always adapting. Not to fear! There are other actions you can take to make your dog’s life easier.

  • Visit the vet! Especially in the early stages when you may not be certain your dog has CIV, it’s important to make an appointment with your vet to check in and test for CIV. Though Dr. Pilossoph says confirming dog flu strains is difficult, a test could help narrow down the problem.
  • Antibiotics or other medicines can be prescribed to ease symptoms and guard against additional infections (like pneumonia if your dog’s immunity is low). Dr. Pilossoph notes that antibiotics are not necessary for dog flu, but some vets may prescribe them if there’s a secondary bacterial infection.
  • TLC also goes a long way. Make sure your sick pup rests, eats and drinks plenty of water. If your dog is coughing or has labored breathing, Dr. Pilossoph recommends nebulization, or placing your dog in a warm, steamy space. “[This] can be useful in moistening the airway and reducing the feeling of coughing,” he says.
  • Supportive care in a veterinary hospital is an option for severe cases. Dr. Smith says this is ideal if your dog is very dehydrated and needs intravenous fluids, supplemental oxygen or monitoring for bacterial infections.

How Long Is Dog Flu Contagious?

Just like humans spread the flu to one another, dogs pass CIV through respiratory droplets in the air and via touch. “After exposure, it can take a few days for clinical signs to appear,” says Dr. Smith. “Yet dogs can spread the disease during this ‘incubation period’ before they appear ill.”

So, be a responsible dog owner! If your dog is diagnosed with CIV, keep her away from other pets and animals. The AVMA recommends isolating dogs infected with H3N2 for at least 21 days​ and dogs infected with H3N8 for at least 7 days to avoid spreading the disease. Dr. Pilossoph agrees that isolation for three weeks after you notice symptoms is a wise choice.

A dog gets vaccinated at the vet before dog flu season
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How to Prevent Dog Flu

The best way to prevent dog flu is steering clear of the virus in the first place. Since it’s so easy to catch and tricky to treat, one of the best ways to do this is through vaccination (basically a flu shot for dogs). Zoetis offers the Vanguard CIV H3N2/H3N8 vaccine, which targets both strains—obviously, talk to your vet about your options.

All of the vets we spoke to recommend making sure your pup is up to date on vaccinations for CIV, parainfluenza, adenovirus and bordetella if you plan to board her or take her to the dog park, which Dr. Smith calls “ground zero” for transmissible infections. Don’t assume your pup is fully covered. Note that even though the vaccine can’t guarantee your dog won’t get sick at all, it will make the symptoms much less severe.

If there’s a confirmed outbreak in your area (or honestly, even if there’s not), washing toys, bowls, beds and leashes frequently is smart. Kill those germs ASAP! If you run into the neighbor’s dog on your way inside, wash your hands before handling your own pup. Even if another dog doesn’t display symptoms, he could be carrying the virus.

The vets we spoke to also note there are immunity supplements on the market that pet parents may want to give their dogs. Dr. Smith warns against believing everything you hear. “Most supplement products are not FDA-approved and thus not quality tested for their ingredients or their efficacy,” she says.

As a more holistic-focused vet, Dr. Pilossoph says foods rich in Vitamins D and C are good at fighting off viruses. If you’re dead set on trying supplements, Dr. Pilossoph says you can try functional mushroom supplements with Chagas, Reishi and Turkey Tail mushrooms or products with Quercetin, an antioxidant bioflavonoid. As always, check with your vet first.

Dr. Danielle Bernal, global veterinarian with Wellness Pet Company, says keeping dogs at a healthy body weight can support a life of well-being but also help reduce the risk of health upsets like respiratory disease. She says 70 percent of a dog’s immune system lives within the gastrointestinal system, so it is important to ensure supplements contain prebiotics and probiotics to support a healthy microbiome.

Dr. Bernal recommends Wellness® Shield Health Supplements for their antioxidants, omega-e fatty acids, mushrooms, prebiotics and probiotics “These chews take a whole-health approach to immune health and seasonal allergy support,” she says.

If your dog isn’t into supplements in pill or treat form, Dr. Contreras recommends foods like unsweetened yogurt, salmon, blueberries, strawberries and oranges—in moderation.

If you are concerned at all that your pet may be showing signs of dog flu, contact your veterinarian and keep your dog at home. Use a pet sitter instead of a kennel if you’re leaving town. You don’t want to be the source of an outbreak! And you certainly don’t want your dog to feel ill.

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Sarah Ashley is a Chicago-based freelance journalist. She has covered pets for PureWow for six years and tackles everything from dog training tips to the best litter boxes. Her...