That is plainly not true. Maybe there are a few hypertrained service dog, but the same "service dog" rules apply to dogs under traying, with no formal checks. So take untrainable puppy from shelter, say you are training it to be "fetch service dog" in 30 years, and that yapper can legally enter anywhere.

I do not buy arguments about hypoglycemia, stroke etc. Moderm electronics are far better at that.