hmmm.
Interesting method of recall! My dog already does have pretty flawless recall, but
only if deers or bunnies run by, will i be unable to call him off mid-chase.
otherwise, we have recall down pat.
I'm actually pretty darn proud of Buddy's recall, long distance, distractions, whatever, he comes running to me, full speed and smiling.
That yanking and having dog associate sheep with your disapproval, might work, it is not what i'd call positive only training, imo. It's not how i'd desensitize a dog to anything at all, ever, but, i bet it might work. I have desensitized my dog to many things, but, not by yanking and scolding.
That method doesn't work with all dogs. My dog is dog-aggressive, and your method as described would not reel my dog back in if he is focusing on another dog. I could spend years yanking on him, and sternly saying "no!" and he would not change an iota. That is eggggzactly what most ppl with aggressive dogs do, for the dog's entire life, and the dog never ever gets better. I can get Buddy back to me, even around dogs he hates, but your method doesn't work for that.
I have zero idea, though, even if i decided to yank and intimidate my dog if he gets too close to an animal,
how to apply that to bunnies and deers. Sheep, might indeed be easier, as they don't dart away with the same speed as bunnies and deers. You approach the sheep, instead of having sheep dart out in front of you in the woods.
I have desensitized my dog to some horses down the street that he used to fear and react towards. (i just got Buddy calm, starting back where my dog WAS comfortable, and rewarded that, moved closer, rewarded that, and so on, no yanking, no scolding or sterness at all) My dog is now cool around horses.

(well, my dog is cool around
those 3 particular horses anyway, no idea if he might react to some other horses..no idea..)
How do you apply this "yank and yell" method to fast running wildlife that you see only occasionally, now and then?
My guy is like you, he will occasionally yank and yell "no" at my dog, when my dog lunges towards squirrels or bunnies. Well, he
used to, he's pretty much realized it doesn't work for Buddy,
and so my guy has quit, after years of that.
doesn't work at all,
not at all.
Plus, overtime, my guy has changed his mind about yanking and loud voices for dogs.
Any ideas for my problem with my dog chasing fast running bunnies and deers? which is not livestock,
(cuz i did desensitize my dog to some horses down the street,
but my dog still chases bunnies and deers)
Got any ideas on
how to get my dog to stop mid-chase after bunnies and deers?
I only ask, as i don't hear a whole bunch of ppl who say they know how to train this. I know very few, and our last dog,
we could call him off a chase, 
although we weren't even very knowledgable back then about training dogs
, we just got lucky with Toby. Toby would just came back even if chasing a bunny,
but not this current dog Buddy, nope. I know some other dogs around here on dogtrickacademy, who also won't stop chasing prey in the middle of a chase. nope. They might be too shy to admit it, but, i know Buddy is not the only dog here who wont' come back if he is after prey.
Til we met Buddy, we did not realize, we can't call
all dogs off of a chase in progress

. who knew?
If Buddy is off leash, and a bunny goes by, he's gone...he brings the dead bunny back to us.
Any ideas for bunnies? and deers zooming by?? Not slow moving livestock that we can approach, but suddenly appearing, zooming, fast moving wildlife?
I've occasionally joked i'll buy some bunnies to train Buddy with!!

but i have no where to keep them and i don't know a thing about how to care for bunnies. And Buddy would still probably chase deer....
