Canine Influenza: Welfare and Prevention

Dog influenza caused by H3N8 and H3N2 strains causes outbreaks in shelter and boarding populations with significant welfare consequences.

Key Facts

Two strains of canine influenza are established in the United States: H3N8 and H3N2
Transmission occurs through respiratory secretions and contaminated surfaces in close-contact dog environments
80% of exposed dogs develop infection but most recover with supportive care within 2-3 weeks
Approximately 10% develop secondary bacterial pneumonia requiring intensive treatment
Shelter outbreaks can require extended quarantine periods causing prolonged confinement stress

Welfare Considerations

Dogs with influenza experience fever, nasal discharge, coughing, lethargy, and inappetence for 2-3 weeks. Those developing pneumonia face severe respiratory distress requiring hospitalization. Shelter outbreaks are particularly welfare-damaging because quarantine isolation extends an already stressful environment, lengthening time to adoption. Dogs with comorbidities including brachycephalic conformation or heart disease face higher complication risk. Vaccination provides meaningful protection in high-risk populations and is particularly recommended for dogs using boarding, grooming, or daycare facilities where transmission risk is elevated.

What You Can Do

Vaccinate dogs using boarding, grooming, or dog park facilities against both influenza strains
Isolate any dog showing respiratory signs and inform facilities the dog recently attended
Ask boarding and grooming facilities about their influenza vaccination and biosecurity requirements
Support shelter vaccination programs that protect entire dog populations during outbreaks