Can Dogs Get Bird Flu? Exploring the Impact of Avian Influenza on Pets and People
Avian influenza, commonly known as bird flu, is a viral infection primarily affecting birds. It has recently gained traction online after reports of indoor cats dying in the USA after eating Northwest Naturals Brand Feline Turkey Recipe. There was a voluntary recall and the state of Oregon put out this statement. The cross-species transmission of avian influenza viruses (AIVs) to mammals, including cats, dogs and humans, has raised significant concerns among scientists, veterinarians, and public health officials. While historically considered a bird-specific disease, several subtypes, such as H5N1 and H7N9, have demonstrated zoonotic potential. With the recent recalls coming to light and cat deaths what does this mean for dogs?
Understanding Avian Influenza Viruses
Avian influenza viruses are categorized into two main groups based on their pathogenicity in birds: highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI). HPAI strains, such as H5N1, are of particular concern due to their high mortality rates in birds and their ability to infect mammals. Dogs, historically not considered susceptible hosts, have shown increasing vulnerability in recent outbreaks.
Canine Susceptibility to Avian Influenza
Recent studies indicate that dogs can become infected with avian influenza viruses, particularly H5N1 and H3N2 subtypes. A study published in Emerging Infectious Diseases (Songserm et al., 2006) documented the first confirmed case of H5N1 infection in a domestic dog in Thailand. The dog had consumed infected poultry carcasses, highlighting the oral transmission route.
Symptoms in Dogs
Dogs infected with avian influenza often exhibit respiratory distress, coughing, nasal discharge, fever, and lethargy. In severe cases, pneumonia and systemic infection can occur, leading to high morbidity and mortality rates. A study by Zhu et al. (2015) demonstrated that H5N1 can replicate efficiently in canine respiratory tissues, causing pathological changes similar to those observed in avian and human cases.
Transmission Risks
Transmission among dogs appears limited, but studies have shown the potential for virus shedding through saliva and nasal discharge. This raises concerns about dogs acting as intermediary hosts, potentially facilitating the adaptation of avian influenza viruses to mammals, including humans.
Human Infection with Avian Influenza and symtoms
While human infections with avian influenza remain relatively rare, the consequences can be severe. The World Health Organization (WHO) reports that H5N1 has a mortality rate exceeding 50% in infected individuals. Human infections often result from direct or close contact with infected birds or contaminated environments.
Human symptoms vary from mild respiratory distress to severe pneumonia, multi-organ failure, and death. Early symptoms often include high fever, cough, sore throat, and myalgia. In some cases, encephalopathy and neurological symptoms have been reported.
Can Dogs Serve as a Bridge for Avian Influenza to Humans?
A key concern is the ability of avian influenza viruses to mutate or reassort with human-adapted influenza strains. Studies, such as those published in Nature Reviews Microbiology (Gao et al., 2013), emphasise the pandemic potential of reassortant strains, which could acquire efficient human-to-human transmissibility.
One of the critical questions in avian influenza research is whether dogs could serve as a bridge species, facilitating viral adaptation and transmission to humans. Dogs are in close contact with humans, and their potential role as viral reservoirs cannot and should not be ignored.
Evidence from Research
A study by Chen et al. (2016) found that H5N1-infected dogs could shed the virus in their respiratory secretions, albeit at lower levels than infected birds. This suggests that while dogs may not be primary transmitters, they could contribute to viral persistence and mutation.
Additionally, a serological survey conducted in China revealed that dogs in poultry-dense regions had elevated antibodies against H5N1, suggesting frequent exposure.
Preventive Measures and Public Health Implications
For Dogs:
Avoid feeding dogs raw poultry, especially from unknown or uninspected sources.
Avoid feeding dogs raw milk
Limit dogs' access to environments where infected birds may be present.
Regular veterinary checkups and surveillance for respiratory symptoms in dogs.
For Humans:
Practice proper hygiene and handwashing after handling birds or poultry products.
Use protective equipment when in contact with potentially infected animals.
Report any unusual respiratory illness to health authorities, especially after exposure to birds.
Research Gaps and Future Directions
Despite growing awareness, significant gaps remain in our understanding of avian influenza's behavior in dogs and their potential role in zoonotic transmission. Longitudinal studies and enhanced surveillance are essential for identifying high-risk scenarios and predicting viral evolution.
Conclusion
Avian influenza poses significant risks to both dogs and humans, with growing evidence supporting cross-species transmission. While dogs are not primary hosts for avian influenza, their role as intermediary hosts and viral reservoirs cannot be overlooked. Ongoing research, combined with preventive measures and increased surveillance, will be critical in mitigating the risks associated with this zoonotic disease.
As scientists and veterinarians continue to uncover the complexities of avian influenza, public awareness and proactive measures remain our most effective tools in preventing a potential outbreak. Remember, just because something hasn’t happened to your dog does not mean the risk is not there. Both pet owners and public health officials must remain vigilant in the face of evolving viral threats.
(As a Canine Nutritionist I DO NOT recommend Raw Milk and will be advising against feeding raw poultry during any avian flu out break.) If you have any concerns please speak to your vet or feel free to e-mail me sally@thecaninedietitian.co.uk