Regarding the policy with walking your dog in Belgium it is a local police regulation that can differ from one place to another; however the main rule is that you are responsible of your dog and therefore recommend to be on leach.
When walking in the woods, they should be on leach too and the main hunting season is depending of the location but usually from 15 Sep to 31 Dec . and it should be post signed too.Sign posts to look out for:
The yellow one above is notification of date and time and the red one is forbidden due to hunting period.
A useful link here.
Provided by the HNLO