It was only a matter of time before pigs would become part of the discussion involving avian flu.

But what does a poultry disease have to do with pigs?

Some scientists are concerned that pigs could act as “mixing vessels” for avian flu and other flu viruses, which could transform them into diseases that spread to and among humans. United Kingdom scientists are now talking with the nation’s farmers about restricting movements of pigs and poultry as they consider the prospect of avian flu entering the country.

Interestingly, Europe’s free-range production trend for both pigs and poultry have raised concerns that migrating birds may drop avian flu onto domestic farms from other countries.

Officials in the Netherlands have ordered free-range chickens to be moved indoors. The European Commission is considering a directive were governments could cull pigs if an avian-flu outbreak surfaces.

Now, free-range pork and poultry production is not at the same level in the Unites States as in Europe. But the trend is on the rise.

The avian-flu risk to hogs is fairly low, but it does bring into question production practices that put pigs and poultry not just on the same plot of land, but also within a general production area—or even state. Imagine the issues that could arise in terms of transporting pigs in and out of areas exposed to avian flu. A common speculation is that trucks and trailers are the more likely vectors of exposure to the disease.

While avian flu is not a big concern for U.S. producers at this point in time, zoonotic diseases are generating growing recognition and discussion, and it’s largely driven by avian flu.