It's nice to find a place full of chihuahua people! My boy casull (everyone calls him castle) is 6 years old and full of attitude. He's had a very traumatic past and it's left him full of stress and fear aggression. He and I have been inseperable since he was just a tiny 2 month old and lived with friends of mine. Thewould potty got him as a friend to their 1 year old son, he was picked up by the tail, grabbed around the neck, they didn't supervise their interactions and it got to the point he bit their son and they wanted to get rid of him. My sister was looking for a chihuahua for her deployed husband at the time and she took him home. My oldest nephew started screaming at him as soon as he got home from work, my sister locked him in a kennel alone downstairs in the dark (he was used to sleeping with someone so he cried a lot) than she yelled at him until he stopped and my nephew got up in the morning to go to work he sat in front of the kennel kicking it with his boot and being an ***. I got on my nephew about being a jerk and I tried talking to my sister. About a week later she wanted him to stay with me because he was snapping at the kids (he wasn't potty trained they were smacking his behind when he potty in the house) it scared him so he started to snap back and she would than have him smacked again. It took me no time to potty train him, I've never laid a hand on him and I've been working very hard on his fear aggression towards....... Everything. It took me a long time to get him ok with kids and he's finally started not snapping at them.My other sisters niece stays with me during the day and when she falls asleep he has started guarding her to the point he will bite me if I come close to her and I don't know what to do. It's started happening when she's in time out and I don't want to scare him more but I want him to know it's OK that I'm not going to hurt her. He has ivdd, diagnosed three years ago and part of me wonders if it's from all the smacking he got. Most of my family don't like him and it's hard to explain that he's scared he's not being mean. I've read books on fear aggression, does anyone size have this problem and have any advice? Thank you everyone!