Also known as: Dog flu
Canine influenza is a contagious respiratory infection caused by influenza A virus strains H3N8 and H3N2. Because the virus is relatively new to dogs, most have no natural immunity, allowing rapid spread in groups. Illness ranges from a mild cough and nasal discharge to fever and pneumonia. Severe disease and death are uncommon but can occur, especially with secondary bacterial infection.
Canine influenza, or dog flu, is a contagious viral respiratory infection caused by influenza A subtypes H3N8 and H3N2. It can resemble kennel cough but is a distinct viral disease.
The virus spreads through respiratory droplets, contact, and contaminated surfaces. Outbreaks are common in shelters, kennels, and daycare facilities. The H3N2 strain can also infect cats.
Most dogs show a persistent cough, nasal discharge, sneezing, lethargy, and reduced appetite. Some develop high fever, and a minority progress to pneumonia with labored breathing.
PCR testing of nasal or throat swabs early in illness confirms infection, while paired blood tests can detect antibodies later. Radiographs assess lung involvement.
Care is supportive: rest, fluids, and good nutrition. Antibiotics treat secondary bacterial infection, and severe cases may need hospitalization. Recovery usually takes two to three weeks.
Vaccines against H3N8 and H3N2 are available and recommended for at-risk dogs. Isolating sick dogs and disinfecting shared areas limit outbreaks.
This content is for educational purposes and is not a substitute for professional veterinary advice. If you are worried about your pet, contact your veterinarian.
