Not emotional support, but there are dogs who's job is to aid physically disabled people.
Emotional support animals are cheaper substitutes for a rich social and family life.
Discussion
I've never seen a real legitimate support animal. I've seen plenty of fake ones.
Ive seen service animals for
- helping guide blind or visually impaired people
- detect and alert to medical conditions (e.g. siezures)
These are quite rare though.
Service dogs are completely different and appropriate and come in many forms.