[Hope]

I recently had my 4 1/2 year old male neutered on advice of two vet's due to having possible medical problems in the future. Since I did not title the dog, I decided this would be the best for his life span since many vets feel it is really cruel and potentially dangerous to keep an intact dog without breeding him. Three months later and he is now exhibiting extreme Dog on Dog aggressive behavior, even with females, which he never EVER had a problem with prior to the neuter. Granted, he was always nasty with other intact males, but he had loads of patience with puppies and bitches before, now he has no patience for any dog.

A little background: The dog has been trained in OB and does not show undeserved aggression towards people. He is constantly socialized in the area that I live in and comes in contact with lots of adults and children. He is well behaved on and off lead (won't tolerate anything else) as I made sure to train him in both respects. The issue becomes off-lead dogs that are not controlled by OTHER owners.

I am not so concerned about dog on dog aggression as I am dog on human aggression (though I imagine it can escalate). But, having said that, I feel like a heel when someone's unruly dog comes running up to us and my dog acts aggressively, not to mention I would not like him to harm another's dog.

Positive note: He now has all of his drive back, so much so people often think he is about two years of age. He is eating A LOT, but does not gain any weight, which is a plus.

What to do? The only thing I can think of right now is to muzzle him, but then I am concerned that people will stop wanting to pet him, like he is some sort of man-eating animal. Then I am concerned that another dog may attack him while he is muzzled? I am at a loss. The only thing I can think is that his sex drive kept him in line with the social structure around other dogs, and without it, he has simply chosen not to have patience for any dog. Any advice please would be greatly appreciated.