Can anyone help me to understand dog aggression? DO you know of any books or websites I can read about it? Why do they need to attack other dogs? What makes them do it???

I took Josie to my cottage and I had her tied up cause there are people and dogs. She managed to break her tie out and run directly to a big german shepard and have a huge scrap with it. Now, I hear 2 females will fight to the death...and seeing the gsd was huge I'd say she would have won.....(this is Nikki for anyone who saw the pics of her and Zeke playing) anyway, Josie would lose I'm sure. She's an 8 yr old and Nikki is almost 2. I went in and grabbed Josie and pulled her off. I know they can turn on you but I'd rather have a bite then no dog.

Jo was limping a little but she seems fine now. Nikki is fine too. I'm just afraid either a) bigger dogs will kick her ass no problem and b) someone will tell me to put her to sleep. I cannot live without Josie. She is my life and it breaks my heart to see that I obviosuly can not train her. I know it's my fault she's like this...and I don't work with her enough or something I don;t know.

I spend $400 on training to help her. She was doing so well too...

After it happened I went inside and cried for a while. It's so scary and I need it to stop. I don't care if she never likes dogs...I JUST want her to listen when I say "no" or "come"

I don't think I'm fit to own dogs. I just ruin them. -sigh-