Good afternoon to everybody,
I don't know how the dolphins helped the boy, but In my opinion and according with the press it's possible that the contact with the mammals has been important to start a new form of physical communication that helped him to show /explain to the others his great expirience with his new friends. Not having done a personal expirience I can't say if this therapy may have helped him, by the way the result are evidents.
I know the pets therapy, and the horses too. I think that in each of them it's important the contact with the animals.
It's not easy raise up an amount so important, but today I think that's possibile by the social networks and involved a lot of people, like friends, family etc.