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)

Share

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

Ask Dr. Paola- Help! My Dog Gets Reoccurring UTIs (March 9, 2026)

Welcome to our “Ask Dr. Paola” series, where every Monday we bring expert advice straight from Dr. Paola Cuevas (MVZ) to help our...

DIY Repellents for the Dog Who Thinks Everywhere Is His Toilet

Dog urine and everything nice have a complicated relationship. One thrives, the other suffers, and if you’re reading this, you already know which...

Dogster’s Weekly Photo Contest Winners: I Dig, Therefore I Am (March 5, 2026)

Every week our team gets the privilege of sorting through our readers photos to choose what dogs will win this weeks contest! See...

Ways to Stop Dog Boredom Before It Destroys Your House

Your dog is staring at you. They’ve paced between the door and the couch. They’ve sighed dramatically from their bed. The message is...

More related

9 Best Puppy Training Treats in 2026 – Reviews & Top Picks

Training a puppy or young dog can be a very arduous process. It takes time, patience, and consistency. Luckily, our canine pals are...

10 Common Dachshund Teeth Problems: Vet-Explained Causes, Signs & Treatment

We love Dachshunds for their fiery personalities and doleful eyes. Animal care workers will tell you they can be a handful but only...

How to Get Rid of Fishy Smell From Your Dog: 6 Vet-Verified Reasons & Tips

A dog that smells fishy is considered unusual, and a fishy smell usually comes from your dog’s mouth, skin, ears, or perianal or...

Can Dogs Have Matcha? Vet-Verified Dangers & FAQ

Matcha can be found in a plethora of food and drink items, from lattes to ice cream. If you’re a fan of occasionally...

Keep reading

Can You Return Dog Food to Petco? 2026 Guide & FAQ

Whether you are considering trying out a new dog food from Petco, or you’ve recently had an issue with food you purchased, you may be wondering if the store will accept returns. Dog food can get quite expensive, and if...

Petco pet shop

Crave Dog Food Review 2026: Recalls, Pros & Cons

Review Summary Crave dog food is a newer brand that offers dry and wet food formulas. The brand promotes grain-free diets and features meat-based lean proteins. Like all AAFCO-approved brands, Crave offers complete and balanced nutrition for dogs. As with...

Dogster_Crave Dog Food Review

Can I Buy Dog Food Using Food Stamps (SNAP)? 2026 Guide

As the economy continues to struggle, many families are finding it difficult to make ends meet. One way that some people are able to save money is by shopping for groceries using food stamps. However, is it possible to buy...

woman buying dog food

Can Dogs Eat Carne Asada? Vet Reviewed Facts & FAQ

You may be familiar with the phrase “puppy dog eyes.” That is why saying “no” to a dog is next to impossible when they want something, whether they want to play, get up on the couch with you, or eat...

Can Dogs Eat_carne asada

10 Best Dog Foods for Medium Dogs in 2026 – Reviews & Top Picks

There are so many options for dog food on the market nowadays that it’s easy to feel overwhelmed by all the choices. The good news about the many varieties of food is that dogs that suffer from allergies can find...

beagle dog eating from bowl

Is Sportmix Dog Food Made in the USA? What You Need to Know

Sportmix dog and cat food are manufactured by Midwestern Pet Foods, a subsidiary of Nunn Milling Company, Inc. This is a fourth-generation, family-owned business that started in 1926 in Evansville, Indiana. All Sportmix pet food formulas are made exclusively in...

pouring dog food in food bowl

Can Dogs Eat Crickets? Vet-Verified Facts & FAQ

Crickets are insects that belong to the Grylloidea family.1 They typically have long bodies, segmented legs, and large antennae. A tough exoskeleton covers their bodies and provides protection from predators. They can be found almost everywhere in the world except...

Can Dogs Eat_Crickets

Can Dogs Eat Tripe? Vet-Reviewed Dietary Guidance

Tripe is the lining of a ruminant’s stomach, which includes cows and sheep. It is safe for human consumption, although it is considered an acquired taste with many people balking at the idea of eating it. Tripe, in the appropriate...

Can Dogs Eat_Tripe

Love Dogs? So Do We! Join the Dogster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Dogster Email Newsletter