How are canine influenza viruses spread?

• A. All of the above
• B. Direct contact
• C. Fomites
• D. Aerosol transmission

Answer: (A)

Canine influenza viruses spread through multiple routes, not just one. Direct contact is a key way they move—an infected dog can pass virus to another through close interactions, including sharing saliva or nasal secretions during sniffing, kissing, or play. Fomites matter too—virus can survive on surfaces and objects like leashes, collars, grooming tools, kennels, or water bowls, so a healthy dog can pick it up by touching or sharing contaminated items. Aerosol transmission plays a role as well, especially in crowded or enclosed spaces, where respiratory droplets or small airborne particles containing the virus can be inhaled by nearby dogs. Because all of these pathways can contribute to spreading canine influenza, the option that reflects all of the above is the best answer. In real-world outbreaks, transmission often involves a combination of direct contact, contaminated environments, and close-range aerosols.