I just adopted this 1 1/2 year old Lab/corgi mix a few weeks ago. He's always been extremely friendly to everyone. He has some weird obsession with other dogs- whenever he sees a dog, he starts pulling and crying, wanting desperately to play. I've been taking him to the dog park up until a couple of weeks ago when he was neutered. He absolutely loved it and would run around for hours playing with all the other dogs.
Well now that his surgery has healed, I took him back to the park. Everything was fine until some huge dog started being very dominant, roughly chasing him around and biting at his scruff. My dog looked scared, so I leashed him and started leaving. Another dog come up and started sniffing him on the way out. My dog looked uncomfortable and then one of them growled, not sure which. The owner took him and started leaving, and as they walked by, my dog growled at his dog.
I shrugged it off and took him back today. Not long after, some poodle walked up and started trying to mount him. My dog started growling, which I don't blame him, but he never used to mind it and then shortly afterwards, he started growling and chasing a nice unrelated dog.
What is going on?? How do I stop this? I'm terrified he'll try to bite someone's dog if I bring him back again. Could he be nervous and traumatized because of the dog yesterday trying to dominate him? This is completely out of character for him! He's not snarling or anything, it's more of a low guttural growl, but a growl nonetheless. :/