if I where you I would take an air horn or a large bottle with stones on your walk. That way, if a fox comes near you then you can just give a quick blast or throw the bottle on the ground to spook it and it will probably develop a scare for humans!
http://dsp.imageg.net/graphics/produ...97594p275w.jpg
^^ see link.
Probably a bit of an extreme measure, but I wouldn't want to risk anything!