fear agression?

Question
Hello -- we have a 2- yr old retriever mix we got from a shelter 3 months ago.  For the first 3 weeks he was the friendliest, sunniest dog we ever had and knew basic commands of sit and was generally well-mannered but he did chase cats and squirrels and would usually not come when called when off the leash. So we had a "highly recommended" dog trainer come to the house to work on this.  Before she came he was diagnosed with heartworms so he had had heartworm shots 5 days before the trainer came.

The first thing she did before she even got in the door was try to flip him (later saying she needed to assert herself as the boss) and when she grabbed his back he growled and then snapped at her.  She insisted on continuing the training (but did not touch his back again)  and after awhile he was ok with her but leery.  She said she needed to come back in a few weeks to work on the agression once he was out of pain.

After she left that day he began being agressive when people came to the house and now he is agressive with any stranger who tries to pet him.  he hasn't bitten anyone but he will growl and even snap sometimes. If we tell people he's afraid and to just ignore him he's ok and ignores them and will eventually come up and sniff them and become friendly (but sometimes this takes more than one visit).

Is this something we can work through by just quieting him and saying NO or will he always be like this? Or are there other things we should do?  We've decided not to have the trainer back as she seems to have caused the problem but should we reconsider this?

Now that this has happened I've been reading all I can on this and I realize that there were other things wrong from the beginning -- we spoiled him horribly, giving him treats just for breathing and hugging and praising him constantly and although he's always been very friendly with us even at the beginning he tried humping us and anyone else he encoutered which I now understand is a move of agression.

Any advice you can give would be appreciated.  We don't want to take a chance of him biting anyone and although we love him we don't want to worry everytime we have him out for a walk.
thanks.


Answer
Humping is NOT aggressive behavior, it's just status seeking behavior, and can be rude, but not something that a dog should be "attacked" over.  In fact, some clasping behavior is actually considered affiliative.  You were wrong to hire a trainer without asking what methods would be used on your dog, but it's good that you have elected never to have that person work with your dog again.  Alpha rolls, and other such tactics are discouraged by the American Veterinary Behavior Society and other professional organizations that study behavior.  Meeting aggression with aggression, or being aggressive with a fearful dog always makes things worse.

The way you handle this is to use desensitization and counterconditioning techniques, to convince your dog that unfamiliar humans are not scary.  To learn these techniques, I suggest getting a copy of Patricia McConnell's book, "The Cautious Canine".  It's very inexpensive, and gives very clear instructions.

Your dog is smart - he learned in "one trial" that people could be scary. If you don't make progress using the book, try speaking to a behavior counselor from IAABC.