Was wondering and hoping to hear experiances on this.
When your dogs see deer/animals running away and go to chase them whats chance you can call them off when they already alerted to the moving animal?
Proof and Kuniva will peel right off them with a "Leaveit!, Come!" except for on a rare occasion when they are yards away and the deer jumps 2 feet in front of thier nose 
but they are not perfect and I do not expect them to be, they dont go for long but the return is delayed in thier excitment. Grim is young and I dont put him in the situation to have that happen because Im not confident I can call him right off, but if a deer jumps out anytime soon ill call him and tug his fishing line if need be then have a happy party in the woods on his return with treats, toys and letting him chase me
My friend against my advice let her lab loose with my dogs while we excercised them on acreage by my grandmas, well a couple of deer float jumped out of the brush our dogs gave chase, I called my boys off and got them in a heel, she called her dog and he went, fast into the woods after them, we walked and called for a half hour before he finally came back wet nd tired. She was terrified and leashed him and asked why he didnt come back with mine. I answered you havent solidified his recall. Shes been working on him since and quit releasing him with false confidence.