I don't have a service dog, but I do have 2 "service" cats, one is my personal masseur, he's better than any PT out there, just gives a few little sniffs and starts his attack on the offending muscle group. He'll curl up over it with a low rumbling purr, make sure it's all nice and warm then start kneading away with little acupuncture taps occasionally and if it cools down he'll curl up again till it warms up nicely again. He wasn't trained to do any of it, got him as a kitten from someone desperate to find him a home, but couldn't imagine keeping my sanity some days without him. My other cat isn't the sharpest tool in the shed, but he loves opening and closing doors for his mommy, of course sometimes he closes them in my face, but he's too cute especially when he realizes his mistake and becomes frantic to open the door again without thumbs it's a real challenge for him if he shuts it too hard. He also retrieves hair ties for me, and loves to pull them out at night, about the only line I draw with his bid of helpfulness is when he wants to retrieve any food that falls on the floor, it's been slow work teaching him not to pick it up and drop it back on my plate. But both are amazing since neither were trained or even really encouraged to be the little helpers they are. I know a dog, even trained service dog is beyond my capabilities to care for, but my cats are excellent nurses and super low maintenance, they can care for themselves better than I can and yet still find time to take care of me too.