I would say,
IF IN DOUGHT, KEEP YOUR DOGS OUT.
If brock is about you should be able to find nearby trees scratched with their claws.
if your near a fence, run the back of your fingers along the undersde of the wire and you should feel any hair stuck to the wire.
normally the run up to the hole is worn like the M1 motorway.
is their any dung pits along the run.
is their any paw prints around. if yes, are they fox, brock or what.