Service Animal Defined by Title II and Title III of the ADA. A service animal means any dog that is individually trained to do work or perform tasks for the benefit of an individual with a disability, including a physical, sensory, psychiatric, intellectual, or other mental disability.

The key here is 'do work or perform tasks'. As a driver, you can ask "What work or task is this animal individually trained for." Their answer will allow you to determine if the animal is considered a 'service animal' under the ADA.