Abstract:
As identification of H5N1 highly pathogenic avian influenza virus (HPAIV) outbreaks in mammals increase, there is a growing concern that the virus will spill over into the human population. H5N1 HPAIV has been a panzootic and public health concern since 1996. Although few cases of H5N1 HPAIV have been reported in dogs, hunting dogs that retrieve waterfowl are a high-risk group due to their physical contact with the environment, wildlife, and human handlers as well as previously documented infections with other influenza strains. This study is a combination of a primary cross-sectional study and secondary national study. In the primary study completed in 2023, blood serum was collected from Washington State hunting dogs and analyzed for H5 and N1 subtypes of HPAIV. Surveys completed by dog owners detailed the dogs’ retrieving activities and health background. A secondary national survey of hunters from January to mid-March 2024 characterized the types of interactions and relationship humans maintained with their hunting dogs along with contact between hunting dogs and other dogs. Descriptive analyses of the primary study (n=192) revealed 57.3% of participants did not have their hunting dogs vaccinated for CIVs and 18.8% did not know if their dog had a history of CIV infection. Descriptive statistical analysis of the secondary national survey (n=112) indicated that a majority of participants considered their hunting dog as part of the family (93.8%), but not as a pet (57.1%). Of dogs that lived inside the home and slept in the same room as their owners, 67.5% also slept in the bed. When considering the use of personal protective equipment (PPE), 96.4% of respondents did not utilize PPE when handling a sick dog and 81.3% did not use PPE when handling harvested birds. An exploratory analysis of the primary study utilized logistic regression models to determine the risk factors associated with H5N1 HPAIV infection in hunting dogs. From the exploratory analysis, the odds of a hunting dog infected with H5N1 HPAIV was 20.28 times greater for dogs that retrieved sick birds in the past 12 months compared to dogs that did not retrieve any sick birds (95% CI: 3.15, 217.30). Findings from this research demonstrate the complex, sustained physical and personal connections between individuals and their hunting dogs. Additional research utilizing a One Health approach is necessary to ascertain the risk factors associated with H5N1 HPAIV infection in hunting dogs and to enhance our understanding of the environment’s role in the transmission of H5N1 HPAIV. Results from this study provide a unique understanding of the interactions between humans and their hunting dogs, and the potential to leverage the well-being of hunting dogs to protect public health as well by identifying opportunities to introduce preventative measures to reduce the risk of zoonotic disease transmission events.