3 yr old male suddenly aggressive towards toddler-very worried!!
I've been a long time lurker. Harry, my GSD is a 3 year old neutered male that I've had since he was 8 weeks old. He loves all of my kids (I have 5) and he has never ever shown any aggressive behavior towards them. He has been socialized not only with my tribe of kids but the neighborhood kids as well since we had him at 8 weeks. He loves kids.
We recently got a new puppy a month ago, a female. Harry and Lucy get along great. I practice NILIF with Lucy though I've been laxed with Harry letting him on our bed and couches. I still make him wait before he can go outside and that type of thing. Lucy is contained in the house until she can be trusted (potty and chewing). She has an ex pen that she hangs out in and a crate I feed and keep her in at night. Harry gets to roam the house because he's earned our trust that is until last night. Harry got into Lucy's ex pen when I wasn't watching which is hard to to do with 5 kids and took her bully stick. He took it into our living room and our 2 year old toddler walked in and must have grabbed it. He didn't growl but nipped our daughter hard on the hand. It didn't draw blood but there were teeth marks. I scolded him and put him in his 4x6 kennel we have in the basement for a time out for me and for him. I know our daughter should not have taken away his high value treat and I should have been watching them closely but again he has never done this before. I chalk it up to next time I will give him bully sticks in his kennel so this doesn't happen again and up my training a bit but it made me extremely upset and nervous that he did that in the first place. I've also closed Lucy's ex pen so he doesn't go in there and steal them.
The other incident which really upset me was today he's on our bed which I allow for him to sit with me up there while I was talking to my husband. My toddler wants up so she can pet Harry. I get her up and she lays over Harry to pet him as she does a million times before this and he growls and barks at her. I immediately take her away and make him get off the bed. I'm very worried about this sudden behavior.
I will call our vet to make sure there is nothing medical going on and get him checked out. I don't know if it is the puppy coming into the family and shook things up? He's in kennel for right now until I can watch my toddler with him. I can try tethering him to me but I also do that with our puppy. I've included Harry when I do training sessions with our puppy who's 12 weeks. He also gets plenty of excercise, chuck it ball, walks, and he still loves the flirt pole. We also play "find it" which he loves. How can I fix it this if it isn't medically related? We love Harry and see him as a family member but my kids come first.
Thanks for any advice.