01105: Understanding the Dynamics of Canine Influenza Virus Transmission in Dog Populations and Intervention Strategies for Reducing Transmission

Grant Status: Closed

Grant Amount: $104,220
Cynda Crawford, DVM, PhD; University of Florida
January 1, 2009 - December 31, 2011

Sponsor(s): Akita Club of America, Inc., American Brittany Club, American Shih Tzu Club, Inc., Basenji Club of America, Inc. & Basenji Health Endowment, Basset Hound Club of America, Inc., Border Terrier Club of America, Boston Terrier Club of America Charitable Trust, English Springer Spaniel Field Trial Association, French Bulldog Club of America, Irish Wolfhound Club of America, Inc., Komondor Club of America, Mastiff Club of America, National Beagle Club, Poodle Club of America Foundation, Pug Dog Club of America, Inc., Scottish Terrier Club of America, Silky Terrier Club of America, The Yorkshire Terrier Club of America, Inc., Westminster Kennel Club, Yorkshire Terrier Club of America Foundation, Inc.

Breed(s): -All Dogs
Research Program Area: Immunology and Infectious Disease
Donate to Support this Research Program Area

Project Summary

Canine influenza is a highly contagious respiratory infection of dogs caused by a novel influenza A virus of the subtype H3N8. H3N8 canine influenza virus (H3N8 CIV) has caused respiratory disease outbreaks in thousands of dogs located in 38 states in the U.S. Although most dogs recover from an influenza-like illness, many develop a debilitating pneumonia that can be fatal if not treated under hospital care. There is little information on risk factors for canine influenza, either for individual dogs or for facilities that house dogs. In our first epidemiological study, location in the Northeast and West regions of the country and housing in animal shelters and boarding facilities were identified as risk factors for H3N8 CIV infection of dogs. We are currently completing a second epidemiological study focused on identifying kennel facility parameters such as population density, source and frequency of introduction of new dogs, sanitation practices, disease surveillance and infection control protocols that may increase the risk for canine influenza outbreaks. Since shelters are a risk factor for virus exposure, we constructed a mathematical model to simulate H3N8 CIV transmission in shelters to determine factors important to development of outbreaks and establishment of endemic infection. This study identified indirect virus transmission by contaminated fomites and the number of dogs housed in the shelter as the most important factors promoting canine influenza outbreaks. Isolation of sick dogs, vaccination against canine influenza, vaccination and isolation combined, and stopping admission of new dogs were four common intervention strategies applied to the model to determine their effect in reducing or preventing virus transmission. Analyses indicate that neither isolation nor vaccination alone or in combination can completely eliminate virus transmission in a shelter under the modeling conditions employed. However, these strategies can reduce the number of infected dogs during outbreaks. While stopping admissions of new dogs did not prevent outbreaks, this intervention strategy prevented establishment of endemic infection in the shelters. An individual-based model to simulate H3N8 CIV virus transmission in dog shows was also developed. Overall, the model as constructed had an excess of infectious contacts, thus reducing any one mode of virus transmission did not necessarily have a strong effect on the number of infected dogs leaving the show. The number of infected dogs leaving the show was most affected by the probability of contact between all dogs, either by direct transmission of virus between dogs or indirect virus transmission by fomites, including contaminated judges. Increased efforts to decontaminate judges only caused a slight reduction in the number of infected dogs. However, there was a dramatic decrease in the number of infected dogs when at least 90% of the dogs were vaccinated against canine influenza prior to the show. The overall results of these studies provide valuable information to dog show organizers and kennel facility managers for guiding the formulation of policies for prevention and control of canine influenza.


Anderson, T. C., Crawford, P. C., Dubovi, E. J., Gibbs, E. P. J., & Hernandez, J. A. (2013). Prevalence of and exposure factors for seropositivity to H3N8 canine influenza virus in dogs with influenza-like illness in the United States. Journal of the American Veterinary Medical Association, 242(2), 209–216. https://doi.org/10.2460/javma.242.2.209

Help Future Generations of Dogs

Participate in canine health research by providing samples or by enrolling in a clinical trial. Samples are needed from healthy dogs and dogs affected by specific diseases.

Learn How to Help

Get Canine Health News:
Please leave this field empty
American Kennel Club Canine Health Foundation, Inc

8051 Arco Corporate Dr.
Suite 300
Raleigh, NC 27617

Tax ID# 13-3813813


© 2021 AKC Canine Health Foundation | Privacy Policy | Site Map

Site by Blackbaud, Inc.