Families with dogs in Chicago and other parts of the midwest have been taking precautions against an outbreak of canine influenza that has sickened over 1000 dogs. Veterinarians were treating it on the assumption that the flu was caused by a subtype of the H3N8 virus, which first emerged in greyhounds in the US in 2004. Cornell University has announced that they had determined that the outbreak was actually caused by a virus closely related to Asian strains of influenza A H3N2 viruses, currently in wide circulation in southern Chinese and South Korean dog populations.
Should Cat Guardians Care About Canine Influenza?
By now, you’re probably checking to make sure you’re on the right blog. Why would you be reading about the dog flu where you normally read only about cats? The H3N2 virus isn’t exclusive to dogs; it can be transmitted between species to cats.
At the beginning of 2010, cats in an animal shelter in Seoul, South Korea caught the H3N2 canine influenza virus from dogs in the shelter who were also ill with the virus. In this first known outbreak of the disease in cats, 100% of the cats in the shelter became ill, and 40% did not survive.
A subsequent study published by the International Society for Influenza and other Respiratory Virus Diseases verified that cats can acquire the H3N2 virus both from dogs and from other cats. Importantly, the study also verified that transmission of the virus doesn’t require direct contact. Cats in the study acquires the virus by respiratory droplet (airborne) transmission, too. Once infected, cats shed the virus, making them contagious, for up to seven days.
Most reported clinical cases of H3N2 virus have been severe, but antibodies have been found in significant numbers of healthy dogs and cats, which suggests that some animals have milder illnesses. Symptoms in cats include elevated temperatures, lethargy, and respiratory signs including nasal discharge, conjunctivitis and abdominal breathing.
Precautions You Can Take
The American Veterinary Medical Association (AVMA) recommends that sick dogs or those showing signs of respiratory illness be isolated from other dogs. Because dogs are most contagious in the two to four day incubation between exposure and before showing signs of illness, they also recommend isolating dogs known to have been exposed to dogs infected with the H3N2 virus from other dogs. Knowing that this can be transmitted to cats, you can take the same precautions and isolate your sick or exposed dogs from cats, as well.
You can help prevent spread of the virus by good hygiene such as hand washing and by through cleaning of shared items such as blankets and bedding. Influenza viruses do not usually survive in the environment beyond 48 hours and are inactivated or killed by commonly use disinfectants.
References and further reading:
Cornell University, Midwest Canine Influenza outbreak caused by new strain of virus
Journal of General Virology, Interspecies transmission of the canine influenza H3N2 virus to domestic cats in South Korea, 2010
International Society for Influenza and other Respiratory Virus Diseases, Inter- and intraspecies transmission of canine influenza virus (H3N2) in dogs, cats, and ferrets
Iowa State University Center for Food Security & Public Health, Canine Influenza
AVMA, Canine Influenza: Pet Owner’s Guide