Your precious Fido could be hiding a dirty secret. Traditionally, new influenza viruses have been linked to bushmeat or farm animals, especially when reared intensively. Think pigs and swine flu or birds and avian flu. But the truth is the origin of the next pandemic could be much closer to home – man's best friend. That's the conclusion of a study recently published in the journal mBio.
Influenzas, such as the devastating Spanish flu, arise from so-called reservoirs in the animal kingdom. These are species that "host" the virus. In these hosts, pathogens can replicate before being transmitted to other organisms.
Fortunately, in the vast majority of cases, the influenza virus can only transmit to individuals of the same species. However, under extremely rare circumstances, a random mutation may allow a particular virus to "jump" to another species, just as it did before the Spanish flu pandemic of 1918 – a disease that originated in wildfowl.
Birds and swine are commonly considered to be major sources of potentially dangerous pathogens. Horses and dogs, on the other hand, are not. But a new study challenges this assumption.
Researchers tested 800 canines in the Guangxi region of southern China for influenza viruses. These were dogs that had been brought to the vet between 2013 and 2015 with respiratory problems. Of those, they found that 116 were infected with influenza, some with variations of the swine flu virus.
After analyzing the genetic composition of 16 samples, they found that some of these swine flu viruses had spread through pig and human populations in the past. It's problematic because this mixing can produce a level of genetic diversity and this genetic diversity can turn the virus into a pandemic threat.
“The more diversity of viruses there is in an animal reservoir, the higher the chances that it will lead to a version of the virus that is able to jump,” explained study co-author Adolfo García-Sastre, reports Science News.
“We now have H1N1, H3N2 and H3N8 in dogs," he told Medical News Today. "They are starting to interact with each other. This is very reminiscent of what happened in swine 10 years before the H1N1 pandemic.”
What's more, the evolution of the canine-hosted flu virus has occurred in just a few years, he said. I.e. extremely rapidly by evolutionary standards.
However, the study was completed in just one region of China and involved a relatively small number of dogs so cannot indicate whether the situation is widespread – there's certainly no need to panic just yet. It is important to stress that influenza viruses have NOT yet made the jump from dogs to humans. The researchers do, however, advise government and public health organizations to start monitoring influenza in pups and continue to research vaccinations and other infection-control processes.