thats to stop cats going in your yard. and since foot and mouth zoo's
arent allowed to sell it any longer. i rang longleat and asked about it.
good garden centres sell some sort of lion poo by-product called roar
thats meant to do the same job. but considering this thread is about
foxes i dont suppose this information matters much :-)

Like most animals that spray scent as a marker for their territory, you can
overcome it by spraying the area down with some strong discenfecant like
Izal or even Zoflora. I'd put it down neat around the worst prone area.
The animal is (1) likely to be put off by the smell and (2) won't recognise
the area as their own and will probably avoid spraying it.