Interesting point there. Whilst our cats pretty much stay on our property (not that we could prevent it if they didn't want to) we are having an issue with a local neighbourhood cat that keeps coming onto our property, not only that, but a couple of times over the last weeks we have come home to find it in our garage holed up one of our cats or, on 2 occasions, actually inside our house on our furniture... Its hard because we have cat flaps for our cats, but works the other way when you have intruding cats.
So that comes back to what you say, that animals can carry it, and it shows how easy it would be to spread to people no matter how hard they are trying to be diligent... tough times indeed...
I have a sureflap and that works perfect, only my cats can enter the house. It scans their rfid chip en only unlocks the door when it's a registered cat.
