My T has a dog and she said she occasionally brings him in because she is trying to train him to be a therapy dog. I've only seen him once though. I think she didn't have many clients that day and generally avoids bringing him when she'll be there late.

He was really well-behaved though! He came over to me and I pet him for a minute or two and then he went over to her and laid down. I would have preferred it if he had been by me though