When you are in Paris, it is probably a correct statement to say that you are not going to have your own car, so you want to make sure that any transportation that you have allows your dog. Taxis and cabs are normally the ones that do not want any animals in their cars, so make sure that you call and ask in advance – that way, you can be sure that you are not breaking any rules.
You also want to make sure that if you are going on the Metro or Bus that your dog, if small enough is in a lap carrier. Larger dogs need to have a ticket with them, generally a children’s ticket.
You also want to make sure that you know where you can take your dogs. Open air markets are places that pets are not allows and neither are restaurants or museums.