I'm so sorry. That must have been very upsetting. Although I guess pup is probably better off at the rainbow bridge than suffering out on the street.

This reminded me of something that happened at work today (yes! I am currently doing two weeks work experience at a veterinary surgery. Was going to start a topic about it, because it's VERY exciting and I'm learning a lot, but it just never eventuated). A black lab came in as an emergency - he's 14, pretty old for a lab. He'd had a seizure and was drooling, yelping, crying and trying to writhe off the table, and before they could get the IV drip into him he'd shut down completely into a coma. They thought it'd be kinder to put him to sleep at that stage, so we called the owner, but the owner told us to keep fighting for the dog and she was on her way. By this stage the dog's gums were ghost white and his breath was cold.
Anyway, to cut a long story short, after a LONG battle they found a vein and got some fluid into him, and I had to hold him on the heat mats once he regained consciousness, because he kept writhing off them (he was shaking so bad the table was moving ).
If you're wondering, he's in a stable condition at the surgery now. They think he's going to be fine, but it's doubtful how good his quality of life will be after this.

Sorry Amy, this might not be relevant to this thread, but I thought it sounded quite similar (both elderly labs and all).