Unless it’s a service animal (e.g., a Seeing Eye dog), only small dogs in closed containers can board a subway, bus, or LIRR train. Metro-North trains allow small dogs that are leashed and controlled. With taxis, it’s the driver’s call. Improve your chances by picking the dog up before hailing the cab, then assure the driver it’s well behaved, and tip extra. Medium or large dogs have virtually no chance with taxis, so call Pet Chauffeur (866-738-7433) or Pet Taxi (212-755-1757).