You mentioned service dogs. As program director of the the largest funder of service dogs for veterans in Canada, I can tell you that it's a misunderstood field in many ways. A service dog, although it can change and literally save lives, has to be introduced into a stable environment.
Often what happens is that you have somebody reaching out in desperation for something. The additional cost and having to care for a dog.... As anybody who has a pet dog knows, it takes a certain amount.... The in-clearing has to do a proper job of making sure that the house is stable enough to support that dog so that the dog can do the work. If you end up with a person who is marginal having a service dog, it's an extra burden on that individual.