Good Dog Walking Areas:
The Sihlwald area is a nature preserve, excellent paths, well marked, and you can walk for hours. Many sections say only to walk the dog on the leash either for Nature Preserve or for protection from hunters. However, a well-behaved dog and a concientious owner can find plenty of room to let the dog off the leash and have a lot of exercise.
There is a train to Sihlwald, or at the very far end to SihlBrugg. There is parking at the Naturzentrum, and in local streets and lots in Gattikon.
Das Naturzentrum Sihlwald (in german)