Hi everyone- New lab mama here and brand new to this forum! I have used this forum quite a bit while raising my 8 month old yellow lab, Charles, but it seems like this problem we are now facing needs a post of its own. A back story on Charles: I rescued him very unexpectedly from a breeder/puppy mill who was eventually shut down. (May 2019) He was 4 months old when he found his way to me. I immediately enrolled him in Puppy School with a certified dog trainer and he has completed his classes. (he actually did very well and was the best behaved pup there). I travel weekly for work and I still live with my parents, so it has been a family affair looking after Charles. When I travel for work, I take him to a Woman's house who boards dogs for a living. (I think this may come into play later in the story-the boarding started in July of 2019) The first few months of having Charles, he was incredible. I felt almost jinxed that I ended up with SUCH a sweet, good little puppy. Not one accident in the house, loved being social and meeting others and other dogs, never chewed anything in the house (up until recently that is) and was a cuddle bug. My parents have a little 9 year old shih tzu who is the queen of the house and she has never been trained or socialized. She absolutely hates any dog with a vengeance. She will growl at Charles and instigate. Charles has usually just tried to play with her or paw at her, or he would generally ignore her.. until this evening. Our Shih tzu took it upon herself to snag Charle's bone when he walked away. Charles saw she had his bone and walked up to her, she started to growl and show her teeth (all while holding his bone) and Charles growled back, showed teeth and he seemed to have put his mouth around her neck. her neck was damp. This is the first time he has ever showed true aggression towards her. She cried out of fear, but he did not hurt her. We took a flash light and checked her up and down. Since I have had to board him for work, I have only noticed one other time when Charles was aggressive. He is OBSESSED with balls. Actually obsessed- like a drug. He has never had a problem at the dog park before. A puppy walked up and tried to take his ball, and same thing, Charles growled and seemed to go for his neck but not actually bite? I have no idea where this is coming from and I have no idea what to do. I dont know if this could be coming from the other dogs at boarding? I have asked the lady who watches him and she insists its not a problem. This is not like the sweet little but I know. He is not aggressive towards humans at all. I have taken a steak bone out of his mouth (i know you are not supposed to do this!, but I would never be scared to have my face down near his. I feel that if I reach out to the trainer, she will either try and get me to come back and pay for classes or just give me flyers/blogs on aggression. Has anyone had similar experiences with this? Any tips, comments, stories or words of encouragement are appreciated. I am feeling a little helpless right now!