Sorry to hear about your dog Brian. I lost my dog 5 years ago... one weekend he just started fainting and falling over, wouldn't eat and started vomiting... and this dog was usually just a ball of energy... my parents took him to the vet as soon as they could get a hold of him... and he never came back... his heart was beating at 15bpm (I think it's bradycardia), and the vet kept him , saying he only had a few hours left and that he would make sure he would go without any pain...
it's a hard decision to make in your case - just make sure that your dog isn't in any pain - my heart goes out to you man

Edit: JV - tears came when I read your reply - sorry to hear about your recent loss

__________________
///ichelito