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 Canada Pet Adoption Statistics & Facts to Know in 2025

Note: This article’s statistics come from third-party sources and do not represent the opinions of this website. Ask any pet owner, and they’ll...

How Long Do Mini Australian Shepherds Live? Average Lifespan, Data & Care

Several factors affect the lifespan of various dog breeds. Some are controllable, such as diet or veterinary care. Others will play out because...

Do Dogs Have Zodiac Signs? Pet Horoscopes & Personality Traits

Zodiac signs are all the craze nowadays. It seems that everybody knows about astrology and even judges people based on their astrological sign....

Why Do Dachshunds Hate Rain? 5 Potential Reasons & Tips

You can’t blame Dachshunds for hating the rain. It’s not always fun to walk in the rain, and their disdain isn’t unique to...

More related

Should I Divorce My Husband Because Manic Loves Him More? Maybe!

Hi, I’m Allison. Read my introduction to learn more about me and my three mixed-breed dogs from Thailand, Jelly, Lorraina, and Manic. I...

Wheaten Terrier vs. Goldendoodle: Differences Explained (With Info & Pictures)

These two dog breeds are extremely different. The Wheaten Terrier is a purebred dog, while the Goldendoodle is a mix between a Golden...

Can Dogs Be Nearsighted? Vet-Approved Signs, Diagnosis & Treatment

Nearsightedness, or myopia, is a refractive disorder that makes far-away objects look blurry. So, can dogs be nearsighted? The answer is yes, in...

Beagle Pain Syndrome: Our Vet Explains Steroid-Responsive Meningitis-Arteritis

Steroid-responsive meningitis-arteritis (SRMA) was initially referred to as Beagle pain syndrome. It was first identified in young laboratory Beagles that demonstrated clinical signs...

Keep reading

Can Dogs Eat Fritos? Vet-Reviewed Facts & FAQ

Dogs aren’t well-known for their pickiness, and it’s up to owners to monitor the food they can access. Just as you wouldn’t eat a bowl of Purina, your pup shouldn’t be making a habit of feasting on the foods we...

Can Dogs Eat_fritos

How to Keep Your Dog From Eating Other Dogs’ Food: 3 Vet-Approved Methods

Feeding time is already frustrating enough without dealing with a food-stealing dog. Luckily, several proven methods improve your dog’s behavior around mealtime. We’ll try to cover a variety of approaches, and hopefully, one of them will be perfect for you...

golden retriever dog stealing food from another dog's bowl

Can Dogs Eat Rice Cakes? Vet-Verified Nutrition Facts & FAQ

Rice cakes are a very popular snack that is often used as a lower-calorie alternative to bread, crackers, and chips. Since we frequently find ourselves wondering what foods in our pantry are safe for our dogs to eat, it’s important...

Can Dogs Eat_Rice Cakes

10 Best Puppy Foods for Labs in 2025 – Reviews & Top Picks

So, you are on the hunt for the best food for your brand-new Lab puppy. Choosing the best puppy food for your new puppy is a very important decision, since getting the proper nutrition is important for bone development and...

labrador retriever puppy eating food from bowl outdoors

Can Dogs Eat Almond Flour? Vet-Verified Nutrition Facts & Portion Awareness

Almond flour is an alternative to wheat flour that, in humans, is considered healthier because it has fewer carbs, contains plenty of nutrients, and has a naturally sweeter flavor. However, while almond flour isn’t toxic to dogs, and it can...

Dogster-Can-Dogs-Eat-Almond Flour

Can Dogs Eat Eggs With Cheese? Vet-Reviewed Health & Nutrition Guide

Feeding your dog tasty treats is one of the simple joys in life, and as many dog owners will attest, it’s even more fun when you and your pet can share the same meal. If you’ve just made a delicious...

Can Dogs Eat Eggs With Cheese

10 Best Dog Foods for Sensitive Stomachs in 2025 – Reviews & Top Picks

Finding the right dog food for your dog can take time, and it’s extra challenging when your dog has a sensitive stomach. Pet food companies are all regulated by the Food and Drug Administration (FDA) to ensure that they are...

fluffy dog eating dry kibble from elevated bowl

6 Best Dog Foods for Shiba Inus in 2025 – Reviews & Top Picks

As with most pets, the Shiba Inu is at its healthiest when eating high-quality dog food that is specially designed to meet its needs. This breed is energetic but also prone to becoming overweight due to being a small breed...

Shiba Inu dog eating from stainless steel bowl