The law does not require leashes for all dog breeds. Only dogs categorized 1 and 2 and other animals must be tethered in the public sphere.
In the forest and in the woods, it is obligatory to walk with your dog on a leash outside the forest paths during the period from April 15 to June 30. For so-called dangerous dogs, the regulations are clear (article L211-16 of the Rural and Maritime Fishing Code) Must be muzzled and kept on a dog by an adult.