Berlin it's a super pet-friendly city. There is even a mall only dedicated to pets!
If you are walking on any street in Berlin you'll notice that everybody has a dog. And the best part is that they're allowed in several places: coffee shops, libraries, restaurants, and almost every way of transportation (buses, trams, subway, trains..).
You'll also notice there's many breed dogs, but the big majority of them are not-breed dogs (mongrel/mutt?), so I think there is some kind of encouragement policies from the government about adopting not-breed dogs. How lovely isn't it?