Oh - perhaps it could have been a coagulation test. I remember the emergency vet on the phone talking about that and some other test too, I think.
Anyway, I guess once we saw (heard) the results of his clotting, when we took him in the 2nd time when he was very ill, we knew it was the poison because we knew that he had eaten it for sure. I guess if you had no idea why your dog was sick it would not help as much. I see what you were trying to say now.