It offers two different services including a Pet Therapy Dog Program and an Emotional Support Dog Program. Three templates for service dog letters from healthcare professionals, covering the types of letters service dog users may legally need.Service dog means a dog trained to do work or perform tasks for the benefit of a mobility impaired or otherwise disabled person. How to fill out the PTSD Service Dog Program Prescription Letter? Thank you for your interest in volunteering as a pet therapy team at Middlesex Health. Researchers have been studying in recent years whether trained service dogs can help war veterans with posttraumatic stress disorder. A paper that people with animals come in that tells the difference between a service animal and an ESA, for example, and establishes rules.