Any animal that you prefer can be your therapy animal.
Besides goats being therapy animals some other animals that can be therapy animals are Dogs, Cats, Horses, Pigs, Rabbits, Lizards, Ferrets, Guinea Pigs just to name a few.
If the animal provides you therapy then the animal can be a therapy animal for you.
Therapy animals such as those listed above including the goats provide affection and comfort to individuals in hospitals, nursing homes, and other facilities.
It's unlikely you'd be able to bring a goat into a hospital or nursing facility but at home they can be your therapy animal.