James,
the training is basically the same as for CGC but with some adjustments for wheelchairs, crutches, canes, and hands that may not be as soft and gentle as they once were. The dogs need to be totally responsive to all basic obedience commands both verbal and hand-signal.
The two major certifying agencies are Therapy Dogs International and The Delta Society. Dogs certified through these two agencies need to pass a field test but the handler needs to pass written tests as well. The team is certified together. Rowdy is certified by both TDI and Delta since different facilities look for one or the other. He may be the only dual-certified dog (of any breed) in the Southeast. Certification brings with it $5 million indemnification coverage from each organization should there ever be an incident while the dog is working.
Clearly, with that amount of risk riding on the dog that gets certified, these organizations aren't simply going to let any dog go into schools, hospitals or convalescent homes without thorough testing and complete confidence in the Team's ability.
Keep in mind that we encounter other dogs often when we're working so Rowdy needs to be bullet-proof with people of every age, race, color, ethnicity, language but also with dogs and cats that he might meet while at a facility.
Therapy work is some of the most rewarding time I've ever spent with any of my guys. If you've thought about it, then find a tester and get your dog certified and then spend some quality time bringing joy to people who may not experience enough of it.
Jim