new aggression in formerly calm grey

[carlak]

I've had my grey for 2 1/2 years- got him at 2 years old. He's always been calm around other dogs. We have 2 cats and he hardly notices them. We've been going to a large open off leash dog park since we brought him home and he has always gotten along fine with the other dogs. So..(you know what's coming)- all of a sudden within the last few months he has gotten increasingly aggressive with other dogs. The  first time I thought it was just because it was a puppy that was getting in his face- he didn't just growl or bark- he pinned the dog down. I got him away and took him home. With increasing frequency at the park he is initiating aggressive behavior- even at old dogs who appear to be no threat at all. The only other accompanying different behavior he is exhibiting is burrowing in the dirt with his nose quite often- something he never did before. For now I've decided I can't take him to the park but it does worry me not to be able to run him- he still LOVES to run and is used to getting that exercise most days. He is listless if he doesn't get to run. I can think of no changes in our situation or environment that might be triggering this behavior.  Any advice???

[lurcherlot]

When there is such a definate change in the behaviour of a dog, I would always recommend a check up at the vets. There is usually an underlying problem.

[sharonhigh45]

I agree with Liz, you need to investigate what could be causing this, I hope you find the answer and he goes back to his normal behaviour.

[kamkay]

Another vote for the vet here

[Carol 47]

I think if there are no changes that could account for this new behaviour, then i would also suggest a vet visit , as he could be in pain from a tooth , ear, or just generally feeling not well , which even in us, can alter the way we behave, cant it ? . So pray that you are able to get to the bottom of this , and, whatever is bothering him, is soon sorted

Carol x

[ragsysmum]

Hope vet can come up with some answers for you.