Anyone else’s dog suddenly aggressive after a few months together?

I brought my 13-month-old Boxer pup home from the show circuit a month ago. He had been with a professional handler since late March and was in a kennel before that. The first few weeks went smoothly with my two other Boxers, but then my 8-year-old male attacked the pup. They got tangled, and the pup ended up biting him. It’s been pretty stressful, and now the pup has started lunging at the older dogs. What should I do to stop this behavior?

That sounds rough. Could it be jealousy? Maybe Freddie’s not used to being with other dogs after being in a kennel for so long.

Carmen said:
That sounds rough. Could it be jealousy? Maybe Freddie’s not used to being with other dogs after being in a kennel for so long.

Yeah, I think jealousy could be a part of it. But I’m wondering if it’s more about him wanting to protect himself after the other dog attacked him?

I’ve heard that the ‘nothing in life is free’ method can help. You might want to try that with the older dog. Maybe it will make things more balanced at home.

puppyt said:
I’ve heard that the ‘nothing in life is free’ method can help. You might want to try that with the older dog. Maybe it will make things more balanced at home.

That sounds like a good idea. I wonder if it would work for Freddie too, since he’s been a little dominant.

Maybe the pup is still adjusting to the home environment. Has Freddie shown signs of being fearful or nervous before? Could be he’s still trying to figure out where he fits in the pack.

Jane said:
Maybe the pup is still adjusting to the home environment. Has Freddie shown signs of being fearful or nervous before? Could be he’s still trying to figure out where he fits in the pack.

No, Freddie’s never been fearful or nervous. He’s been really confident since we brought him home. It’s more about him trying to assert himself now.

Sounds like Freddie might have been spoiled a bit by the professional handler. Maybe work on some basic commands to reinforce your role as the leader.

Smart said:
Sounds like Freddie might have been spoiled a bit by the professional handler. Maybe work on some basic commands to reinforce your role as the leader.

True. I think I need to be more consistent with commands, even though he knows them already. It’s tough with three dogs, but I’ll try it!

Could the older dog’s behavior be triggering Freddie? You mentioned the older dog is very attached to you, so maybe that’s a factor. Separation might help until things settle down.

CyberSage said:
Could the older dog’s behavior be triggering Freddie? You mentioned the older dog is very attached to you, so maybe that’s a factor. Separation might help until things settle down.

You’re right. The older male dog is very attached to me, and I think that might be part of the issue. I’ll keep separating them for now and see how it goes.