[silencio]

there are some reputable training schools (like guide dogs for the blind and canine companions for independence), but there is no real accreditation. there's maybe organizations like assistance dogs international, that hold member schools to standards, but not much beyond that.

the ada explicitly doesn't allow any kind of request for documentation or certification either. basically you just have to take people at face value when you ask them if the animal is required because of a disability. and lots of people with ESAs are okay being very casual about that.

(and the reason i can figure out why people with ESAs are okay with bending the truth compared to a trained service animal, is because they tend to be the ones that are VERY upset in two situations that are legal: the one where i negotiate different accommodations because i'm very allergic to dog dander, and the one where they get upset that a misbehaving ESA is being asked to leave the premises. having been around dozens of trained service animals - i've never seen one misbehave the way ESAs can, and everyone is happy with my suggestions due to my allergy since i go above and beyond, rather than making things more difficult.)