☃ Mason ☃

Why is my Great Pyrenees is aggressive toward my other dogs since he's been neutered?

We just had him neutered 5 days ago. We had to put and e-collar on him and now if one of my other dogs is within 3 feet of him he growls at them. Which is terrifying his two brothers who also just got neutered. Before being neutered he would growl only if they hurt him while playing or something, but now all they have to do is look at him. When we verbally correct him he stops growling until they move again. Why is he so aggressive all of a sudden, and what is the best way to stop this before he gets worse, or hurts one of the other dogs?

Asked by ☃ Mason ☃ on Mar 9th 2010 in Aggression
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Best Answer

Max (aka Sebastian)

Well, it's only been 5 days so it could be a number of things. His hormones are changing as his body gets used to losing his testicles. He may still be in pain or discomfort from the surgery, plus the e-collar is something new, that I'm sure he doesn't like.
all of these things could easily play a role in his new grumpy attitude.
I would keep the dogs apart as much as possible for a little while, so everyone can heal properly.
Besides in the wild, when an animal is injured they are seen as prey so maybe he detects he's not quiet right so his natural instincts are kicking in to be defensive.
It's hard to say. I'd talk to your vet and ask how long you should expect the recovery time to be and when he/they will be back to normal.

Max (aka Sebastian) answered on Mar 9th.

Other Answers



If he is still using the Ecollar, he could just be nervous. I know one of my dogs in the past did this and once he was healed and the Ecollar was gone he got better. If he doesn't have the Ecollar on it could be his hormones changing, but don't quote me on that.

Rambo answered on 3/9/10. Helpful? Yes/Helpful: No 1 Report this answer

Lola Penelope

I would guess its the E-collar. When he is 100% supervised, have you taken it off to see how he responds to the other dogs better, or the other dogs response to him better?

Lola Penelope answered on 3/9/10. Helpful? Yes/Helpful: No 1 Report this answer


how old?
I think sometimes you have problems like this when you have litter mates. They are together and they form their own hiarchy of the whole pack.
Maybe it is time for them to get jobs to do. They could be bored or they could be trying to form the pack order
I would suggest having their own area and a job.
Maybe you could get them into herding and other activities.
see your AKC or herding organizations or a great pyrenees club. There should be a list of clubs that specialize in your breed I find these clubs very helpful for breeds.

good luck.

Dieta answered on 3/9/10. Helpful? Yes/Helpful: No 1 Report this answer


I agree with the others that said he may just be out of sorts because he has his e-collar on.

Also, you know, he's just been through a traumatic experience and surgery and he's more than likely still stressed, both physically and mentally from that.

I think it's highly likely that his aggression is based on protecting himself rather than anything else.

But if he's not better in another week or so, time to call a behaviorist and see if you can't get to the bottom of why he's acting like this. It's hard to say without a full history and without seeing him in person "in action" with the other dogs.

Jack answered on 3/9/10. Helpful? Yes/Helpful: No 0 Report this answer