Here's something has given me something to chew on: While talking to the vet about the fight, how they didn't stop, the length of it and how I had to really scream to get their attention; she said that Chance and Blaze could be responding to my screaming as if I was saying it was wrong for them to be together. I've been pondering the information this evening and I can see that in the dogs actions that the vet could be right.
For example: I was eating a carrot. Both dogs in front of me. But after giving Blaze a bite, she left, letting Chance get the rest of the treat. Blaze. Never. Leaves. If Food Is Present. Never.
So maybe what our vet said was true. And that it is up to me to bring them together and let them know it is OK for them to be together.