Switzerland's approach to off-leash dogs is culturally quite different from Italy's. Italy leans on the sgambatoio, a fenced dog park, as the main place to let a dog run free; Switzerland instead allows off-leash walking in many forests, fields and open areas by default, provided the dog stays genuinely under control, visible at all times, and has a reliable recall.
The trade-off is responsibility shifts more onto the owner's judgement rather than a fence doing the work. If a dog doesn't reliably come back when called, or gets over-excited around livestock, wildlife or other walkers, it's safer to keep it leashed even where off-leash walking is technically allowed.
Watch for posted signs restricting or requiring leashes near forests (see the leash rules article for the breeding-season window), around livestock, and in specific nature reserves — these override the general off-leash default wherever they're posted.