Airlines might be the cause of the majority of the fake service animal, and fake emotional support animal. (Again, it ought to go without saying, but morons can't see the obvious, I am all in favor of the diabetic, the blind, the autistic, etc legit need for service animals) just not bullshit like squirrels and ponies for crazy people

Airlines can charge around a hundred dollars for a pet, but they have to allow "service animals" to ride for free. Without a cage.

So, to avoid the fees charged by airlines for non-service animals pet owners that travels extensively because they can not bear to leave pets home alone....

Or the bullshit emotional support squirrel, bird, and pony nonsense.

It's such baloney that one guy proved a point, by registering a beehive as an emotional support animal. That's how ridiculously unregulated the system is and how crazy people can file and get authorization for nonsense like squirrels, lizards, birds, and insects. 

http://tywkiwdbi.blogspot.com/2019/12/some-people-use-fake-service-dogs.html
https://www.azfamily.com/news/prescott-valley-man-registers-beehive-as-service-animal/