14 CFR Part 382 Nondiscrimination on the Basis of Disability in Air Travel (Air Carrier Access Act): Preamble and Section-by-Section Analysis (with amendments issued through July 2010)

What about a service animal that is not accompanying a qualified individual with a disability?

When a service animal is not accompanying a passenger with a disability, the airline's general policies on the carriage of animals usually apply. Airline personnel should know their company’s policies on pets, service animals in training, and the carriage of animals generally. Individuals planning to travel with a service animal other than their own should inquire about the applicable policies in advance.