As it turns out, our canine friends can become sick with the flu—just like we do. This respiratory disease is caused by either H3N8 or H3N2, two strains of the canine influenza virus.
And just like their human parents, some dogs are more susceptible to catching the virus, explains Dr. Linda Simon, a veterinary surgeon and consultant for FiveBarks. «This includes the very young, the very old, and the unwell. We also know that those who are under stress (such as pets in boarding facilities or shelters) are more prone to catching the flu, as their immunity will be dampened,» she added.
On the positive side, canine influenza is preventable and can be successfully treated—especially when diagnosed early. But first, make sure you know how it spreads, what symptoms to watch out for, and when to call the vet.
What Is Canine Influenza?
As with humans, pets can catch a cold or flu. Dogs (and cats!) are prone to canine influenza, an airborne infection transmitted by viruses. The disease is highly contagious and can easily spread from one dog to another. Its symptoms are similar to the human flu.
“Canine influenza is part of the Canine Infectious Respiratory Disease Complex (CIRD) which describes an acute infection of the upper respiratory tract. CIRD, or its colloquial name ‘kennel cough,’ is the most common cause of acute respiratory disease in dogs and includes several viruses, including canine influenza, Bordetella bronchiseptica, canine parainfluenza, and many more,” explains veterinarian Tori Given Jones.
The H3N8 virus was first detected in dogs in the U.S. in 2004, according to the American Veterinary Medical Association (AVMA). The H3N2 virus is relatively new and was first identified in dogs in the Chicago area in 2015. However, several cases have previously been reported in China and other Asian countries.
Both variations originate from other animals and can spread through the air. The H3N8 canine influenza virus is of avian origin, whereas H3N2 has previously been identified in horses. These microorganisms have evolved over the years and can now spread between dogs.
Fast forward to 2022, the dog flu is widespread all over the world. For example, a recent study conducted in Poland found that 7.25% of the dogs tested were positive for H3N8, H3N2, or H1N1, a flu virus that can infect most pets. As the researchers note, this condition has also been reported in Germany, Italy, and other European countries.
The AVMA says that more than 80% of infected dogs will exhibit clinical symptoms. The remaining 20% are asymptomatic, but they can still spread the virus to others. There’s also a risk of complications, such as pneumonia-like symptoms or even death.
Can Dogs Get the Flu from Humans?
As mentioned earlier, canine influenza is spread through the air, meaning your dog can catch the virus just by being close to his buddies.
The virus can also live on collars, leashes, food bowls, and other surfaces for up to 48 hours, says the AVMA. What’s more, it survives on human skin (e.g., your hands) for up to 12 hours, as well as on fabrics for 24 hours.
Therefore, dogs can get the flu from their human companions if they transport the virus from other dogs they’ve been in contact with.
That’s not the case with the common cold, though, notes the Central California SPCA.
Any dog can get the flu, regardless of his age or breed. However, puppies and senior dogs are at greater risk because their immune system isn’t as strong as that of a young, adult dog. Possible routes of transmission include:
- Sniffing or licking the grass or random objects
- Playing with other dogs
- Sharing his food, toys, or water bowl
- Inhaling respiratory droplets from infected pets or humans
- Touching people’s hands or clothing
As you might expect, the prevalence of canine influenza is higher in kennels, doggy daycare facilities, and pet boarding facilities. Also, dogs with heart or lung conditions and those with short, flat faces are more likely to get the flu, according to the experts at VCA Animal Hospitals.
Unlike the human flu, this airborne infection isn’t seasonal and can spread year-round, reports the AVMA. However, some researchers found a seasonal pattern with peak infections in mid-winter and fall—similarly to the human flu season, notes Dr. Tori.
Also, it’s important to note that humans can carry the H3N2 variant and transmit it to their pets, but not the other way around. To date, there has been only one case of infection with H3N8 in humans. However, H3N2 viral infections are common in human patients.
The takeaway here is that we can’t get the flu from dogs, but the virus may spread from humans to their canine companions, as reported by VCA Animal Hospitals and other organizations.
So, if your little buddy is sick, don’t be afraid to enjoy the winter with him and show your love. Speak to him, cuddle him, and be there when he needs you most.
That said, let’s move on to the next point…
Dog Flu Symptoms to Watch Out for
The H3N8 and H3N2 viruses have an incubation period of one to five days, and most dogs will develop respiratory symptoms within eight days of infection. However, these numbers may vary from one pet to the next.
Dog flu symptoms are not much different from those of human flu. Your buddy may have a runny nose, watery eyes, nasal congestion, or a slight fever. Some dogs also have a persistent dry cough similar to kennel cough.
Other symptoms may include:
- Poor appetite
- Purulent nasal discharge
- Difficulty breathing
- Loss of interest in day-to-day activities
- Fatigue and tiredness
- Sleeping problems
The primary symptom is a persistent cough lasting 10 to 21 days, notes the AVMA. Most dogs will experience this problem even during treatment. “The cough will be dry and non-productive, but owners will sometimes notice that the animals cough with such force that they end up vomiting a white foam,” says Dr. Tori.
Another common symptom is a low-grade fever of up to 40-40.5 degrees Celsius. On top of that, infected dogs can have “a diminished sense of smell, which may affect their appetite,” explains Dr. Tori.
In severe cases, the dog flu can cause a high-grade fever and rapid, shallow breathing. There’s also a risk of pulmonary consolidation, a potentially fatal condition characterized by fluid or tissue buildup in the lungs, warns the AVMA. This symptom is typically associated with pneumonia.
When Should You Call the Vet?
Most cases of dog flu are mild, but you should still call the vet sooner rather than later.
Canine influenza symptoms are non-specific and can resemble those of other conditions, such as bronchitis or kennel cough. Your vet is the only one who can rule out these potential causes and make an accurate diagnosis.
“I would recommend scheduling an appointment with the vet if your pet’s cough is severe enough that they are visibly uncomfortable. It is recommended to see the vet immediately if they have a fever, nasal discharge, a productive cough, anorexia, or lethargy,” suggests Dr. Tori.
Also, beware that canine influenza is fatal in about 10% of cases, reports the MSD Veterinary Manual. Stay on the safe side and contact a vet if your dog starts coughing or feeling unwell out of the blue.
“It’s important to state that all dogs behave differently when ill, so there isn’t a strict pattern to watch out for. However, as a general rule, a dog suffering from canine flu will have a loss of appetite and a disinterest in food, as well as lethargy. If you notice that your dog isn’t getting excited over food, or that they aren’t as high-energy as usual, this is a sign they might be ill and that you should consult a veterinary expert,” says Jacquelyn Kennedy, a canine behavioral specialist and founder of PetDT.
Canine influenza symptoms should subside within two to three weeks, according to the Centers for Disease Prevention and Control (CDC).
But, as discussed earlier, some dogs may develop pneumonia or other secondary infections. For this reason, it’s recommended to call the vet if your furry friend shows any signs of the flu, no matter how mild.
Treatment Options for Dog Flu
Dog flu mimics other conditions, and the diagnosis cannot be made based on clinical symptoms alone.
If your furry friend has been sick for less than three days, the vet will take a sample from his nose or throat. Blood tests are only recommended for dogs who have been sick for longer than a week, says the MSD Veterinary Manual.
As of today, there’s no standard treatment for dog flu. The disease is viral, not bacterial, so it doesn’t make sense to use antibiotics. However, these medications may be necessary in the event of a secondary bacterial infection, explains the CDC.
“Antibiotics are indicated if the patients have a fever and nasal discharge, or if the lungs auscultated abnormally, indicating possible pneumonia. Because the respiratory barrier is adversely affected, this makes the pet susceptible to secondary bacterial invasion aka pneumonia. This disorder only affects approximately 10-20% of the pets diagnosed with canine flu, but it can cause severe damage and is potentially fatal if not treated,” warns Dr. Tori.
Apart from that, your dog will need proper hydration and plenty of rest. The vet may also prescribe cough suppressants, non-steroidal anti-inflammatory drugs, or other medications based on his symptoms. In severe cases, he may recommend treatment with intravenous fluids.
VCA Animal Hospitals suggests isolating your buddy for up to four weeks to prevent him from spreading the virus. Some studies suggest that dogs infected with the H3N2 virus should only be quarantined for seven days, whereas those carrying the H3N2 variant require at least three weeks of isolation.
Also, remember to sanitize your pet’s food and water bowls, toys, leashes, and the surfaces in your home. Consider placing a humidifier in the room where he sleeps to help him breathe more easily.
As a rule of thumb, don’t try to treat your dog with human medications.
How to Prevent Your Dog from Catching the Flu
While there’s no surefire way to prevent dog flu, you can try to limit your pet’s exposure to the virus. Simple things, such as washing your hands after playing with other dogs, can make all the difference.
«If there are any sick animals near where you live or work, stay away from them until they’ve been cleared by a vet. Also, keep your pets away from crowds during public events where people might be carrying around respiratory illnesses,» recommends board-certified veterinarian Melissa M. Brock, a regular contributor to Pango Pets.
Another thing you can do is to make sure your dog gets enough rest.
Sleep deprivation, stress, excess exercise, and other factors can affect immune function, increasing the risk of disease. If you have a senior dog or one with pre-existing illnesses, your vet may recommend immunity-boosting supplements like fish oil, probiotics, or vitamin C.
Don’t forget to clean his toys and blankets regularly. This is particularly important if he shares his things with other pets.
“Depending on the strain of flu your pet has, shedding of the virus can occur for up to 28 days from diagnosis. If you have other pets in the household— and they have been exposed to the flu virus, they may or may not contract it and might have a different immune response to it,” added Dr. Tori.
Last but not least, consider giving your dog a flu shot, especially if you must take him to a pet boarding or daycare facility. Senior dogs and other high-risk groups may benefit from vaccination, too.
How Effective Is the Canine Influenza Vaccine?
The canine influenza vaccine comes in three versions: one targeting the H3N8 virus, one for the H3N2 strain, and another one for both strains. While it doesn’t completely prevent the flu, it adds an extra layer of protection. Its effects kick in within three to four weeks.
However, it’s possible to be vaccinated with one variant of the vaccine and then be exposed to another strain of the flu virus. explains Dr. Tori. Simply put, there’s no cross-protection with these vaccines—unless your dog gets the one targeting both strains.
Flu shots also help protect the lungs and may lower the risk of death in vulnerable dogs, notes the American Animal Hospital Association. Researchers say that «vaccination is the only effective preventive method.» What’s more, it can speed up recovery and reduce the severity of symptoms in infected pets.
But even so, the dog flu shot isn’t a «core» vaccine, meaning that it’s not mandatory or necessary for all dogs.
Dispomed, a veterinary equipment manufacturer, recommends the canine influenza vaccine in the following cases:
- Dogs living in shelters or boarding kennels
- Dogs participating in canine sports events
- Dogs going to grooming or boarding facilities
- Those participating in dog shows
- Traveling dogs, especially those visiting high-risk areas
- Dogs at risk for complications (e.g., older dogs and those with heart or lung conditions)
Note that some dogs may experience allergic reactions to the flu shot. These may include asthma-like symptoms, swelling of the tongue and lips, sneezing, wheezing, or difficulty breathing. However, these side effects are relatively rare.
We hope we have answered your question, «Can dogs get the flu?» Just like their human parents, dogs can catch the flu virus and spread it to other pets. While it’s not possible to eliminate the risk, there are steps you can take to keep your pet safe.
For starters, make a habit out of cleaning your dog’s toys and other personal belongings. Wash your hands and clothing after touching other pets and keep your furry friend away from high-risk areas. For example, it makes sense to avoid dog parks and boarding facilities if there’s a flu outbreak in your city.
As far as vaccination goes, it’s best to discuss your options with the vet. Consider your dog’s age, lifestyle, and overall health, as well as the number of pets in your household.
Apart from that, feed your dog a balanced diet, keep him physically active, and make sure he gets plenty of rest. These small but important steps are crucial for a strong immune system and good overall health.