A little background- my dog is a middle aged yellow lab, I've had him about 4 years, he was from the pound.
He's always been super easy going. I've never know him to pick a fight (or even be willing to fight if another dog has instigated) it's not that he's bottom of the pack, he just doesn't seem to care. He knows he's tougher and never bothered to make a big deal about it.
He's always been slightly possessive of me/our room. He'll sometimes bark if someone comes into my bedroom, but we worked on that this spring and it seemed to resolve quickly. We have 2 other dogs in the family and they all get along great.
A few weeks ago my cousin's lab stayed with us for a week, and my dog was kind of mean to her- which is VERY new behavior for him. Especially when I was around, if the other dog came over near me, my lab would go towards her barking rather aggressively. Nothing ever happened (he never bit her or anything). But I'm worried this is a new and very bad habit. I got mad at him each time and made sure to let him know this wasn't appropriate behavior.
Another dog came over to visit and stay with us last night and we had the same issue. In both cases, the barking only happened when the dogs were in the garage (out in the yard everyone played and was friends).
What should I be doing to get rid of this behavior? I REALLY don't want this to escalate into an issue and I want to end it quickly! He's always been so easy going around other dogs, this is out of character for him.
Any help would be very appreciated!
Cascadia- OTTB mare. 04/04-05/10
If love could have saved you, you would have lived forever
Your dog is being possessive of you, and that can lead to aggressive behavior. When the behavior happens, you need to stop it. Let him know that NO, he doesn't run the pack, and NO, that is not acceptable. Put him in a down/stay, and invite the other dog to visit you. You may need someone on the other end of the leash to enforce the stay part, but make it happen.
He needs to wait for your invitation to be with you, not defend you from everyone else. Clearly he's a good guy, but don't let this blossom into a bigger problem.