As a dog lover, I was curious about what dogs I would see when visiting Paris. I saw fewer than I expected but those I did I encountered in different locations, from promenading with their owners along the wonderful, walkable streets to riding comfortably in shoulder bags.
Other chiens rode the metro tethered with leases to their owners. One large border collie/lab mix was comfortable laying on the floor of one of the metro coaches between riders’ feet and legs. Even beggars on the street had their pups bundled up in blankets on their legs.
Dogs were always on leashes. I didn’t see any dog parks like there are in the US. But people and dogs seem happy and comfortable walking around the cobbled streets and cafes no matter how crowded they are.