Get

In Your Inbox

Dogster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Dog Flu: Signs, Causes & Care Tips (Vet Answer)

dog sad sick sleeping bored

In 2004, the first cases of canine flu (H3N8) were noted in a group of Greyhounds in the US. The virus was identified for the first time in 2005 and is thought to have mutated from a similar strain in horses. It has since spread across the US.

In 2007, another strain of flu (H3N2) from Asia was noted to infect dogs, originally making the jump from birds. Sadly, in April 2015, this virus was identified on US shores and is now also prevalent in many US states. So, if the dog flu is some kind of canine pandemic, how serious is it, and what can you do to protect your dog? Read on to find out more.

Dogster divider_v2_NEW_MAY_24_

What Is Dog Flu?

Dog flu is a viral respiratory illness that can infect any dog. It is spread through nasal discharge and saliva. When an infected dog coughs or sneezes, its fluids contain the virus, which can be transmitted directly to other dogs or objects. The disease is prevalent in dog kennels and shelters.

Contaminated objects can hold the live virus for up to 48 hours, which means the infection can spread through bowls, toys, and leashes shared between dogs or when a dog enters an infected area. People can also spread the virus from dog to dog on their clothing.

Once infected, a dog incubates the virus for 2–4 days before showing signs of illness. They are very contagious during this period, which makes the disease hard to stop. How do you quarantine an infected dog if they don’t show any signs of illness? On top of that, around a quarter of dogs never show any signs of illness but spread the virus for around 20 days.

beagle dog lying on bed looking sick
Image Credit: HelgaBragina, Shutterstock

What Are the Signs of Dog Flu?

As mentioned earlier, some dogs will not show any signs of illness, but about three-quarters will develop respiratory signs, including:

  • Coughing
  • Runny nose
  • Fever
  • Lethargy
  • Ocular discharge
  • Poor appetite

Most dogs will improve in 2–3 weeks. Severely affected dogs can develop secondary pneumonia, which is life-threatening, but the deaths of otherwise healthy animals are very rare. The H3N2 strain is the worst of the two as it seems to cause more severe signs.

Some risk factors make certain dogs more susceptible to severe signs of dog flu. Geriatric or young dogs with naturally weaker immune systems are more vulnerable. Brachycephalic (flat-faced) breeds like Pugs, Bulldogs, and Boston Terriers are more prone to worse respiratory signs. Finally, dogs with pre-existing heart or lung diseases could be affected more by the virus.

Sick Rhodesian ridgeback dog not eating
Image Credit: Zontica, Shutterstock

What Are the Causes of Dog Flu?

Dog flu is an influenza virus, a type that most people are familiar with, some of which can cause the flu in humans. You may have heard of viruses called “H1N1” or “H3N2” circulating in the human population; they are ways of classifying influenza viruses. H refers to the type of “hemagglutinin,” and N refers to the type of “neuraminidase,” both of which are surface proteins.

The viruses are also named for the species from which they were first identified. For example, H1N1 and H3N2 are also known as swine flu, as they originated in pigs. There are two types of canine influenza: H3N8 and H3N2 (genetically different from the swine flu mentioned above).

Dogster divider_v2_NEW_MAY_24_

How Do I Care for a Dog With Flu?

Prevention Strategy

Vaccinations are available against both strains of dog flu, and you should speak to your vet about potentially vaccinating your dog. People with at-risk dogs and those who travel or spend time in group housing should consider vaccinating their dogs, as well as those in more prevalent areas. As with any vaccination, it does not prevent the disease 100% of the time, but if your vaccinated dog were to get dog flu, they would likely have milder signs and clear the infection more quickly.

Seek Veterinary Care

If your dog has any respiratory signs, it’s vital to contact your vet. However, you should seek emergency veterinary care if your dog is very lethargic or has breathing difficulties. Your vet will assess your dog and, if necessary, test for the virus.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's our online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content Savings V1

Your vet will recommend a treatment plan based on your circumstances, but it may include:

  • A period of rest in a warm, comfortable area
  • Access to good food and fresh water
  • Fluid therapy or electrolytes
  • Cough suppressants
  • Antibiotics
  • Imaging or blood tests
  • Monitoring during recovery
  • Hospitalization

Quarantine Your Dog

You should quarantine your dog until they stop showing signs of illness and for at least 4 weeks to ensure the virus doesn’t spread. Quarantine also includes the environment and objects in the environment. If your dog has dog flu, you should change your clothes and wash and sanitize your hands before touching other dogs.

Nebulization and Coupage

Nebulization and coupage is a type of respiratory physical therapy that can help clear respiratory excretions, especially if an infection occurs. You can perform this at home.

Nebulizers create a mist of water to moisten the respiratory tract when your dog inhales it. If you don’t have a nebulizer, hot steam from a shower can work, too. Coupage is when you gently tap the chest to loosen respiratory excretions and help your dog bring them up.

The process should only take 10–20 minutes for your pet to inhale the vapor and about 30 seconds to do the coupage. When doing this, it’s not worth stressing your pet out. If they become stressed or even try to bite, you should stop.

If your dog has pneumonia, your vet may recommend this three times a day for 1–2 weeks. Less severely sick animals might only need this once daily until the signs resolve, but you should ask your vet for specific directions.

Dogster divider_v2_NEW_MAY_24_

Frequently Asked Questions (FAQ)

Dog Flu vs Kennel Cough: What’s the Difference?

Dog flu and kennel cough result in very similar signs, and some people consider dog flu a cause of kennel cough. Kennel cough can be caused by one of many infectious agents, including Bordetella bronchiseptica bacteria, canine adenovirus, and parainfluenza virus.

Can Dogs Transmit Influenza to Humans or Other Animals?

Cats can get the virus from dogs, so they should be included in your quarantine plans. No cases of canine influenza in humans have been reported to date. Influenza viruses commonly mutate, creating new strains that can sometimes spread to new species.

It’s possible for a strain to emerge that could infect people. The Centers for Disease Control and Prevention (CDC) and Health Canada are monitoring the situation.

How Can I Take My Dog’s Temperature?

Monitoring for fever is an excellent way to monitor your dog’s recovery from dog flu. If your dog unexpectedly spikes a fever or the fever does not resolve, they will need veterinary treatment. The best way to take your dog’s temperature is to insert the tip of the thermometer into the anus gently.

You should lubricate the tip with petroleum jelly or another lubricant and have someone hold your dog while you take their temperature. However, please do not stress your dog trying to take their temperature.

Sometimes, it is best left to the professionals. You can try to get a reading by placing the thermometer under their arm, close to their body, but it will be less accurate.

Thermometer for dogs_Olga Anikina_Shutterstock
Image Credit: Olga Anikina, Shutterstock

Dogster divider_v2_NEW_MAY_24_

Conclusion

The canine flu is now prevalent in many areas of the United States. The influenza virus spreads quickly since dogs can shed the virus before showing signs of illness, and some dogs never show signs. As with human influenzas, most dogs show relatively mild signs and recover without complications.

Some dogs develop severe signs and potentially life-threatening complications. At-risk dogs include young and old pups, brachycephalic dogs, and those with other medical conditions. If you’re concerned that your dog is at risk, you can always discuss vaccination with your veterinarian.


Featured Image Credit: Przemek Iciak, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything dog

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Dogster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

10 Famous Dog Photographers: Get Inspired Today

Visual platforms like Instagram have been game-changers for various artistic fields, including photography. While many owners share cute or funny pictures of their...

5 Common Urinary Issues In Dogs: Vet-Verified Facts & Identification Guide

The urinary tract in dogs consists of two kidneys, two ureters, a bladder, and a urethra. It serves many imperative functions, such as...

How Much Raw Food Should I Feed My Dog? Our Vet Explains With Sample Feeding Guide Chart

A raw diet is a nutritional management plan that some owners seek for their pet dogs. The general acceptance of such a diet...

10 Best Dog Treats Containers in 2026 – Reviews & Top Picks

Keeping plenty of dog treats around is a must when you’re a dog owner. It’s a good idea to keep treats handy, especially...

More related

400+ Boy Dog Names for Your Male Pup: Unique & Popular Ideas

Choosing a name for them is one of the most fun things about bringing home a new dog. However, it can start to...

20 Dog Breeds Who Are Escape Artists: Info, Pictures & Origin

All dogs are quite capable of being escape artists, but certain breeds are renowned for their Houdini-like talents. It’s essential to know what...

Golden Retriever Portuguese Water Dog Mix: Info, Pictures, Care & More

If you love Golden Retrievers and Portuguese Water Dogs (and why wouldn’t you?), imagine a mix of the two! This combination results in...

Butternut Box Dog Food Subscription Review 2026: Our Expert’s Opinion

Review Summary Finding the perfect food for your VIP (Very Important Pet) can feel like an impossible challenge. You want something tasty, healthy,...

Keep reading

10 Best Dry Dog Foods in Australia in 2026 – Reviews & Top Picks

Since the dog food industry in Australia is not well-regulated, finding a safe and healthy diet for your pup can be a daunting task. Even if you know you want your dog to eat dry food rather than canned, your...

dalmatian dog eating dry food from a bowl

What Vegetables Can Dogs Eat? 14 Vet-Approved Healthy Options

As dog owners, we have our dog’s best interests at heart and want to keep them safe. One of the biggest risks to their health is what they put into their bodies because some foods are dangerous for dogs and...

Head portrait of a golden retriever dog eating pumpkin slice

My Dog Ate Moldy Food: What Should I Do? Vet-Approved Facts & Signs Toxicity

If your dog has eaten moldy food—perhaps you didn’t store the food properly, or your dog ate the moldy food from the garbage—it is a cause for concern. Mold can make your dog sick, which is why you should take...

Merrick vs. Wellness Dog Food: Our 2026 In-Depth Comparison

With so many different dog food brands and recipes out there, it can be challenging trying to find the right food for your pup. The good news is that if you’ve narrowed it down to Merrick and Wellness, you’re looking...

Dogster_Dog Food Merrick VS Wellness

10 Dog Food Trends in 2026: Pet Food Industry Facts & Statistics

Note: This article’s statistics come from third-party sources and do not represent the opinions of this website. With today’s consumers enjoying better education and more resources to improve their dogs’ quality of life, manufacturers are ramping up their efforts to...

golden retriever dog eating healthy dry food from bowl at home

Can Dogs Eat Bok Choy? Vet-Verified Health Facts & FAQ

Most dogs love it when you offer them something different from their usual diet, and what could be better than healthy treats like veggies? But certain seemingly harmless vegetables can pose health risks to your beloved dog. For example, dogs...

Can Dogs Eat_bok choy

Can Dogs Eat BBQ Sauce? Vet-Verified Facts & FAQ

It’s not a backyard barbecue or beach party without great food and a pup or two. However, not all that food is safe for those dogs. One of those unsafe foods is BBQ sauce, so you must keep it out...

Can Dogs Eat BBQ Sauce

6 Homemade Dog Cake Recipes: Vet-Approved Nutritious Options

Ready to celebrate your dog? These six delicious dog cake recipes will show the world that you love your dog to the moon and back. The best part is that they’re human-grade, which means you can have a slice as...

Freshly baked carrot cupcakes on a plate