I have a service dog for PTSD. I got him when he was 8 wks old and trained him on his tasks and then got him licensed by the city when he was 1.5 yrs old. He's a Yorkie. Service dogs have to know at least three tasks defined by the ADA (look them up they have psychiatric tasks). If they don't know tasks, then they are only an emotional support dog and they DON'T have rights to public access.