holy what the heck!
My 3 year old gsd went after my toddler, one that he's been raised with and has NEVER shown any hostility toward ever. I had put food down for my dog which he refused, as my toddler asked for me in the other room. Maverick followed. As me, my toddler and the high chair with my infant in it, headed back into the kitchen, my gsd rushed toward the kitchen and redirected back at my son. Just nipping, yelping/barking. I'm not sure if he was protecting me or my daughter or trying to keep my obnoxious 2 year old away from his food in the kitchen.
I know the why isn't really the real question into fixing his behavior but here is my problem. The last several weeks I have been putting more and more effort into training my dog. Whenever I do, the kids are with me, not directly (on many occasions I do have my son do commands) as I train him. I've been showing a lot more affection toward my dog, more than usual I'd say. We also have been disciplining our son more because he's getting older and he "knows better". Regardless, I don't know if my dog sees my affection and my son's discipline as a power tool.
Like I said before, he's NEVER been this way toward any of us. The only reason I put the discipline of my son in the mix, because we are not really fond of my mother in law...and I honestly feel my dog feels our hostility toward her, and that is the one person he will nip at if she comes too close. We don't live near her anymore. But that being said, I don't know if my change in behavior is the fuel to the fire.