My Husband and I have a 5 month old German Shepherd named Storm The Behemoth ( which means large beast ). He is an ecceptionaly smart pup. I have trained many dogs and horses, but Storm is completely different. He is not only incredibly smart, but incredibly high energy. He is also very focused on me and does not like me to be out of his sight. The same applies if I have Storm on leash and My husband walks away. Storm has shown some signs of aggressiveness, possessiveness, dominant issuses. With the signs he has shown and the differences I have never encountered with a dog before, I knew I needed some outside help. So we went shopping... to our favorite store eBay...It is true than you can find "IT" on eBay. Among our searching and shopping we purchased a book titled "Dog Training for Dummies " Of all the searches we did through google, this was the most informative book purchased. With this book we have learned what we should look for as he grows and matures, How to stop habits before they have developed, and so many many helpful hints and ideas to not only help you, but your best friend as well. Try reading it!! "Dog Training For Dummies". The other best thing we purchased from eBay was a DVD.. Now this was an AWESOME DVD!!! "Dog Whisperer with Ceaser Millan". This DVD Focused on Aggression, which as I mentioned earlier was one of the signs Storm was showing. The 3 of the 5 episodes were so simular to Storm. This DVD has help us all so Tremendously. Through the book and DVD, we have realized that the signs Storm was showing were from being isolated from the public and other animals. Storm The Behemoth is now attending Doggie Daycare at least twice a week and is doing wonderful with his social skills. AND... I am totally addicted to watching Cesar Millan on TV as much as possible. As for collars, we purchased a slip/choker collar, It does work well, but I think because of his neck seeming to be the same size from top to bottom it is hard to keep the collar at top where it should be. From ideas aquired from both the book and the DVD, we have ordered (Where else, but on eBay of course) what is called a pinch collar. I have had many inputs and ideas, most good, very few disliked them. This is another avenue to try, but well worth trying. To Have A Dog, Is To Be Responsible. We have a dog "which from what the vet and the kennel says" is going to grow abnormally large (150 pound range) for a German Shepherd. So therefore we are pursuing all avenues to assure not only Storm Puppy`s safety but all others that are around Him. Be Responsible, Love Your Friend, Learn All You Can!! Thank You For Looking, Mary & Scott Barnett Maclady65 & Macman75