when lamping off the van mate you need quick dogs to get to the fox(well you do where i live),when we see a fox we just stop in a suitable position to get a run(quickly though), the dogs know there job there gone over the gate, hedge(providing its not to high) or wire.its very rare i stop mate to be honest to squeak them in,but if i do engine off one stops at van and the one squeaking walk down the road away from the van.its worked a few times but the time it takes its easier to drive on and look for an other.
cheers hbg