I've never had a therapist prescribe it, but I definitely know individuals who have gotten a pet for that purpose on their own and I truly believe it is helping them. Sounds like that would be very effective. I wonder if anyone here has had success with that.
My therapist is working on getting all my parts imaginary animal companions for activating attachment and self-soothing. Any type of animal is an option and they can each have as many as they want. A few of us were not sold on the idea but the littles took to it right away and we can all feel the difference. We are no longer as put of by the idea of imaginary comforters. When some of them are getting hugs from their animal I feel a level of relief I've never known before. There was even grief in realizing that I had greater comfort this way than ever as a kid. I was skeptical but it's helping.