
After contacting the Event Host to ask if we could join them, despite the fact that our dog was back in the States, we were encouraged to come. They meet every Sunday at the Bois de Vincennes (the woods on the Eastern edge of Paris), and all responsible dog owners are welcome.
https://en.wikipedia.org/wiki/Bois_de_Vincennes

We had such fun meeting dogs and owners – French and Expats alike. It was great to have some exercise in the green, shady woods, watch the dogs play in the stream, and chat with people who all enjoy travel, love their dogs, and were glad to have us along. I even got to practice my French!