This project has been going on for decades. If smell is a serious issue with foxes, someone certainly brought that up and increasing the scope in this way is rather obvious. In fact it's not really increasing the scope much at all because if you're going for pets, clearly the smell issue needs to be solved.

The primary goal of showing that this can be done at all, apparently has also been accomplished apparently decades ago. I can't imagine that they're not already in the refinement stage.