I wish I had good advice for you. What a terrible situation. It sounds like it's a good thing you brought him home - I'm sure he'd rather be in his home than at the vet.
Good luck with your decision. It's a hard one but only you can make it for you and Taz.
Storm (beeps and has a pink nose and toes),
Misty (with big blue eyes and tasseled ears),
Anya (only ever called Honey - she's that sweet),
Zander (who goes by Punkin' cause he's almost that bright)
Kasee (couch potato who thinks she's a dog)