Alright, I have been reading the 300 and some posts in regards to positive reinforcement and understand that not everyone has success doing the same things. Here is my situation and I really would like your thoughts or experiences... We got Cocoa Anne @ 9 weeks (yorkie), we had her for 4 months and adopted Houdini & Myles (both around 7 years old and yorkies), well Cocoa and Houdini never got along her and Myles grew to play together. After a few months Cocoa started what we believe to be resource guarding and would go after Houdini... Everyone told us to let it go and let them settle it. Well that is what we had been doing, well in the last couple months it has gotten to the point of not just guarding us (when Houdini would sit on our laps) but she would guard the front door so he couldn't come in from going potty, she would guard the family room so he couldn't come in and be with us. The attacks happened more and more and were getting nastier and nastier to where Houdini wouldn't fight back anymore and would get slightly injured. We tried watching over them like a hawk to stop any attack before it would happen, well sometimes we just weren't quick enough and in the middle of grabbing Cocoa would get scratched and bitten. In contacting two behaviorists we were advised to buy either a prong collar or shock collar. We opted for the shock collar. Now this option is working well so far with us only having to shock her a few times in 2 weeks. The attacks have gone from 3 to 4 times a day to maybe once every other day, if that. Now this method seems to be working in this situation but I would be very curious to see what some of the other trainers on here suggest. I have already rec'd an email from Creature Teacher on her thoughts and would love to hear yours.