About 2 months ago we moved into an apartment with our 10 year old pitbull mix and our 2 year old beagle mix. Now the pitbull has always had issues with barking at strangers or people she thinks are trying to invade her space, but since we've moved into our apartment she has begun lunging at people that we pass when we take her outside. We are at our wits end trying to find a solution. Our vet says that there isn't anything wrong with her health. We've tried to train her to ignore people using food and treats but she just ignores us or listens till she gets the treat and goes back to barking or lunging. We've tried no bark collars that let off the vibrations to get them to stop barking, as well as the remotes that emit a high frequency noise. The methods work maybe one or two times before she begins ignoring them. My fiancee keeps threatening to get a shock collar for her and I'd really rather avoid it. Any suggestions would be appreciated.