aggressive behavior after neutering

Question
I have an 8 1/2 month old male standard poodle.  He has never exhibited aggressive behavior until he was neutered 2 weeks ago.  One week after neutering, he jumped up and bit me (didn't break skin, but left a very large bruise).  assumed it was because he was tired of being stuck in the house for a week with a cone on his head.  Since then, when he doesn't want to do what he's told, (e.g. if we have to take something away from him), he will start snapping and attempts to bite.  This morning, at the dog park, he tried to attack 3 dogs (he's been going to this park, with these particular (gentle) dogs for 2 months without a problem).  This behavior shocked me. Can his behavior be attributed to the neutering?  

Answer
Hi Linda;
That is rare, but it does happen.
I have only known a couple of other dogs in my life that reacted badly to spaying or neutering.
He got away with that one bitge, so he has found a way to rule the roost.
When he growls at you, chew him out like you are going to pounce on him and eat him alive.
I mean, really throw a fit about it.

He is little enough to maneuver into a position so you can grab the back of his neck and hold him so he can't get the teeth at you, turn him around and look him in the face as you chew his little butt out.
There could be some mental problems with the change in hormones, but as I said, that is rare.
I will suggest the massages for you too.
It helps with aggression, fears, and a lot of other things.
The calming massage will cure even fear of thunderstorms, and makes it mush easier to calm them so they are not aggressive with other dogs.
I really can't praise these massages too much. They have been the best training too I have ever used, and I really did cure two dogs that were going nuts in a thunderstorm, with a 5 minute massage for each of them. They lay at my feet and slept through the rest of the storm.
I have given tranquillizers during storms etc, and in my experience, the massages do more.
Go to this site and read about the massages, and you can order a video there to learn to do all the massages properly.
     www.lindatellington-jones.com

It will be some of the best money you ever spent.
But as far as the growling and snapping. That is just a kid being sassy. Mom and dad have to make the kid understand that it just won't fly.LOL
When you have to take something away from him, and he growls or snaps, grab him by the scruff of the neck, take it away, and chewing his little butt out all the way, put him in time-out.
Time out at m7y house is a half hour in the small bathroom.
When I let them out, I say "Now you better be a good boy, or mommy will put you right back"
Treat it the same as you would if tyou had a child that kicked you in the shins when you took something away.
He is being a little brat, and will see just how far he can go woth it.
A little would=be dictator.LOL
Charlotte