Transboundary Emerging and Exotic Animal Disease/ Exotic Animal Disease Practice Exam

What is the most likely explanation for the emergence of H3N2 canine influenza in the United States?

1. It arrived in dogs rescued and imported from Asia.

2. It was transmitted from wild waterfowl to dogs in the Chicago area.

3. It was transmitted to dogs due to feeding raw horse meat to racing greyhounds.

4. It was transmitted directly from humans to dogs and then adapted to dogs.

The correct answer is: It arrived in dogs rescued and imported from Asia.

The emergence of H3N2 canine influenza in the United States is most accurately attributed to its arrival via dogs that were rescued and imported from Asia. This particular strain of the virus has been linked to outbreaks in Asian countries, making the importation of infected dogs a plausible pathway for introducing the virus into the U.S. canine population. When dogs are brought over from regions where H3N2 is prevalent, they can carry the virus, thereby facilitating its spread within domestic dog populations. This is particularly significant because dogs do not have prior immunity to this strain, leading to outbreaks when the virus enters a new ecosystem. Infected dogs can shed the virus and infect other dogs, further propagating the disease. While the other options may discuss potential avenues of transmission, they lack substantial evidence or are less likely scenarios compared to importation. The suggestion that the virus was transmitted from wild waterfowl to dogs is less supported, as the primary reservoirs of the H3N2 virus are domestic animals rather than wild species. The idea of transmission via raw horse meat is also less plausible and lacks definitive epidemiological backing. Lastly, direct transmission from humans to dogs, while theoretically possible, has not been evidenced as a primary route of the H3N2 virus