RE: Are some dog owners cheating the service dog system?
I am sure that some of the dogs that come in this way have probably not gone through a service dog training; and short of checking out each supposed service dogs authorization papers, there really is no way to tell if they are or aren't certified.
There is also an authorization that people can get that have no medical issue, but do have an emotional/mental issue; so they need to have there dog along with them to basically keep them on a level mentally. If the animal is not there, they are distraught. It is kind of a companion dog designation, and allows people to take their dog along with them when they travel as well. These dogs do not have to have any special training since they don't do anything except keep their owner company.
Probably, some of the dogs that are being used this way are not actually licensed either, but again, unless you ask for verification each time, there is not much a store can do, and it is often better to just allow the pet than create a big fuss.