Photo by Rous

The Régie Autonome des Transports Parisiens (RATP) runs Paris’s Métro, buses and the commuter-rail RER (Réseau Express Régional) lines. It also runs Paris’s tramway (connecting the 13th, 14th, and 15th arrondissements and the southeast suburbs) and the Montmartre funicular. The RATP’s policy regarding traveling with a pet is as follows (translated below):

“Les animaux ne sont autorisés sur les réseaux de transport en commun que dans les cas suivants:

Les animaux de petite taille, convenablement enfermés dans des sacs ou paniers, à condition qu’ils ne puissent ni salir ni incommoder les autres voyageurs (dimension maximale des sacs ou paniers : 45 cm);

* * *

Sur le RER, les chiens tenus en laisse et muselés.

Attention : Pour un chien muselé et tenu en laisse voyageant sur le RER, vous devez être en possession, en plus de votre titre de transport, d’un billet a tarif réduit correspondant au parcours réalisé et validé lors de l’entrée sur le réseau RER. Dans les autres cas, l’animal voyage gratuitement.”

I’ve left out the provisions relating to service animals. Very roughly translated, the policy states that animals aren’t allowed on public transit except small animals in carriers (no larger than 18″), or, on the RER, leashed and muzzled dogs.

As in the U.S., I strongly recommend that you put your dog completely into her carrier before entering your chosen form of public transit, and keep her in there until you depart. [10/15/13 We’ve been using the Paris metro pretty heavily for the past couple of weeks, and the three other dogs we’ve seen with their owners, all small, have been on leash rather than in a carrier. If a metro official was moved to, s/he could make a fuss, but what are the chances? From the smiles and interest we’ve been getting, I get the impression that using a carrier is actually unusual. We’ll keep doing it because I think Chloe’s happier in it than she’d be in the open — the metro can be noisy and very crowded, and she’s not adept with hopping onto train cars and dealing with closing doors.]

For other posts about traveling with dogs on public transit, take a look at Dog Jaunt’s handy guide!