The “therapy dog” scam is widely used by airline passengers to avoid paying charges to transport the animals. It’s easy to do - just Google up “service dog patches”. A $10 bill and you’re in business.
If you go that route, you’ll end up in jail for fraud.
-Real- therapy [technically, “support”] dogs need a doctor’s ‘prescription’ and have much more limited access than *service* dogs.
People who scam the legitmate system wreck it for those who actually need a support animal.
Therapy dogs are the certified dogs who go to nursing homes and the like.
Support dogs fill the gap left over by trained and licensed service dogs, such as seeing eye, deafness dogs, wheelchair/mobility assistance dogs, etc.