Canine Influenza (Dog Flu): What Every Dog Owner Should Know

Canine influenza, commonly called dog flu, is a highly contagious respiratory disease that spreads quickly anywhere dogs gather. While most dogs recover fully, some can develop pneumonia or more serious complications, making early recognition and prevention important.

What Is Canine Influenza?
Canine influenza is caused by influenza viruses that specifically infect dogs. The two strains identified in the United States are:

• H3N8
• H3N2

Unlike kennel cough, which can be caused by several different bacteria and viruses, canine influenza is caused specifically by an influenza virus.

How Do Dogs Get Dog Flu?
The virus spreads through respiratory droplets when infected dogs:

• Cough
• Sneeze
• Bark

Dogs can also become infected through:

• Shared water bowls
• Toys
• Leashes
• Kennels
• Grooming equipment
• Clothing or hands that have recently contacted an infected dog

The virus spreads very easily, especially where dogs spend time together.

Signs to Watch For
Most dogs develop symptoms within 2–4 days after exposure.
Common signs include:

• Persistent cough
• Sneezing
• Runny nose
• Eye discharge
• Fever
• Lethargy
• Loss of appetite

More serious cases can develop:

• Difficulty breathing
• Pneumonia
• High fever

Unlike kennel cough, dogs with influenza are often noticeably more tired and feel ill.

How Veterinarians Test for Canine Influenza
Your veterinarian may recommend:

• PCR testing (best early in infection)
• Blood (antibody) testing
• Chest X-rays if pneumonia is suspected
• Physical examination and medical history

How Is It Treated?
Because influenza is caused by a virus, treatment is mainly supportive.  Your veterinarian may recommend:

• Rest
• Plenty of fluids
• Anti-inflammatory medications
• Antibiotics if a secondary bacterial infection develops
• Hospitalization and oxygen therapy for severe cases

Most dogs recover within 2–3 weeks.

Can It Be Prevented?
Vaccines are available for both H3N8 and H3N2 canine influenza. While vaccination may not completely prevent infection, it can reduce the severity of illness.

Other prevention tips include:

• Avoid contact with sick dogs.
• Don't share bowls or toys with unfamiliar dogs.
• Wash your hands after handling sick pets.
• Keep your dog home if they develop respiratory symptoms.

How The Blue Hound Helps Protect Your Dog
Respiratory illnesses require proactive prevention.

At The Blue Hound, we help protect our guests by:
✔ Using veterinary-grade disinfectants throughout the facility
✔ Reviewing medical records before visits
✔ Sending wellness questionnaires before boarding and grooming appointments
✔ Requiring sick dogs to postpone their visit until fully recovered
✔ Monitoring reports of contagious illnesses in Cowlitz County and nearby communities, as well as outbreaks reported at surrounding pet care facilities. If your dog has recently visited a location experiencing an outbreak, we may recommend rescheduling to help protect every guest.

While no pet care facility can eliminate all risk, these layers of protection significantly reduce the chance of disease spreading.

When Should You Call Your Veterinarian?
Contact your veterinarian if your dog has:

• A persistent cough
• Fever
• Difficulty breathing
• Thick nasal discharge
• Loss of appetite
• Extreme lethargy

Puppies, senior dogs, and dogs with weakened immune systems should be evaluated promptly if they develop respiratory symptoms.

The Bottom Line
Canine influenza is uncommon compared with kennel cough, but outbreaks can spread rapidly when they occur. Vaccination, staying home when sick, and strong sanitation practices help protect the entire dog community.

At The Blue Hound, we stay informed about local disease activity, screen dogs before visits, and maintain strict veterinary-grade cleaning protocols to help provide a safe, healthy environment for every dog in our care.

Veterinary Sources

• American Veterinary Medical Association (AVMA)
• American Animal Hospital Association (AAHA)
• Merck Veterinary Manual
• Cornell University College of Veterinary Medicine
• University of Florida Maddie's Shelter Medicine Program

Next in the series: Intestinal Worms in Dogs: What Every Dog Owner Should Know