Headline on Yahoo News:

"Horses and snakes join dogs in helping people with disabilities"

"Sorry you're completely paralyzed, Joe. Here's your service anaconda."

Several weeks later:

"Hey- have you seen Joe lately?"
"Oh crap! I forgot to come over and feed his snake!"
"What's that lump....?"


Alternatively:
"Sorry you're completely paralyzed, Joe. Here's your service...Ow! (thud)->gasping<- black mamba..."

Coming soon to a disability service center near you- Service Thestrals, specially trained at Hogwarts!