I used the prong collar with Buddy at the recommendation of
my Vet. I mentioned Bud's pulling on leash when he was about
2 yrs old. Buddy never objected to it at all & would sit quietly
while I put it on before walks. I never considered it a training
device, because it didn't "train" him, but it sure made walks a
whole lot safer for both of us. Never used it for Smokey or
Maggie, but I don't expect them to get as large as Buddy was.