Woobie and Indie seem to be sorting out who is going to be top dog here lately. Indie is 2 1/2 and Woobie will be (or already is) 2 in September-ish. They've always had a sort of standing agreement, Indie gets to be the brute inside the house and generally is more the boss inside and Woobie is more pushy and bossy outside. It seemed to be working and there was never any real scuffles just things like Woobie playing more roughly outside and Indie tending to give him his belly. Inside, Indie will take a bone that Woobie's chewing or a toy or move him out of his space in front of the patio door, etc. Over the past month, Woobie seems to be standing up to Indie more and asserting himself inside. Indie doesn't seem to mind and gives in pretty readily, it seems to be his nature. But Woobie's started to get a bit growly towards everyone. If he's lying somewhere and anyone gets too close, he gives a little grumble and then moves away, nothing too terribly menacing, just sort of like an old man type grumble. Last week at the dog park, he grumbled at a few dogs too and gave an ugly grumble to a puppy that approached. He wasn't near me when it happened, so I don't think it's resource guarding of me, it seems like a space issue, he seems to be defending his personal bubble a bit. And then just the other day he had taken a treat and was eating it on the couch (he eats everything much more slowly than Indie, so I crate them at mealtimes) and Indie approached. For the first time ever, Woobie showed a snarly teeth face and no growl, just an ugly warning scowl, which I'd NEVER seen from him. Should I be concerned? Is this a maturity thing where they are going to sort out who is top dog? Is he starting to be more assertive at the dog park because of an age thing or is it a sign of something to be worried about. He's always been super easy going at the dog park and it's his favorite place on earth, so the grumbling was a surprise. I've never had a multi-dog house before and my previous dog was not dog park material, so I wasn't exposed to how he would handle other dogs as he matured. I've checked Woobie over pretty thoroughly and it doesn't seem that anything physical is bothering him, but I may take him for a look-see at the vet if it's something I should be worried about. Tips?
ETA: He grumbles at other animals
that get in his space, not us humans, just wanted to make that clear.
He's grumbled at the cats as they get close once or twice.