I hadn't thought about the lifespan problem of assistant dogs, the mini definitely has the upper hand there. I'll definitely be looking more into this!
I wonder about the criteria..why are emotional support animals excluded? cats,birdsetc...Certainly a parrot can provide emotional and some fetching services.. I posted such comments on http://www.careresourceguide.com/2011/03/15/new-ada-rules-restrict-definition-of-what-is-a-service-animal-for-the-disabled/
I think its awsome. I wouldn't mind having a mini horse for my Service Animal. When we go to the VA Hospital there are a few ladies who bring in rabbits, & a mini horse for the Vets. It uplifts them, & is soothing. My Service Dog & I stayed in my huusbands room the whole time he was there. He was in the ICU for 4 days, had open heart surgery. After taking Brodie for his walk to potty then on our way back some of the Vets would ask if they could pet Brodie so I let Brodie be also a companion Service Dog. They really enjoyd having us there. We also enjoyd visiting them.