I just adopted a new girl today. She is a 1yr old purebred Rottweiler, AKC registered, the most adorable little stubby girl ever. Her name is Maddy. I assumed when i got her that she would need some training, being around all the new animals and stuff. We already discovered that she gets overexcited when the ducks run or flap. She was friendly, but shy of the cat to begin with but when the cat ran, Maddy ran after her...since then she has wanted to chase the cats everytime. I THINK the previous owners said she was around cats but I e-mailed them again to make sure. She has had obedience & protection training. she's trained to take all her commands in German, but i plan to work with her on English commands too. Her previous owners said she responds very well to a Prong Training Collar, I checked online and found some with and w/o rubber covers on the tips. I have never used one of these collars before so.... Which kind is better? tipped or non-tipped Hert neck is 18", so do I need to buy the 22" collar? Does anyone have experience with breaking a new dog of chasing cats/birds/other things? Do you have any tips, tricks, or methods that worked or helped? Thanks everyone, I really appreciate any help!