Hi XXXXXXXXXX,
Before you take him out in public you have to get him to listen to every command you give the first time you give it so you will want to work daily on training commands in the home, then in the yard, then in the driveway and then you can take him out in public.
It does sound like he may not have had enough dog socialization when he was young or if he did , it was not kept up on a weekly basis,
Dogs that have fear aggression will first try to hide behind the owner and if that does not work to keep him away from what he fears then he lashes out, so you may not have a fear biter if he is going after people/animals right off the bat .
First rule of thumb is to gradually build up what he will be around and that is why you first get all commands down in more non distracting places and build from there. If he acts afraid of something do not coddle him by saying "it's okay" because that is actually rewarding his behavior. You also don't want to pet him or treat him when he is acting that way as that is rewarding the behavior. The reward should come from you when he is acting the way you want him to.
So get a good 'leave it' command down so that he listens to it the first time you give it and when you see people or animals approaching you give that command.This command means his eyes are to be on you and he is to make no attempt to get that which he desires or which frightens him. You can either continue walking past the distraction or you can teach him the down- stay command when a person approaches. To insure he stays in that position at first until he gets it 100% step on the leash just under his neck so he has to stay in the down position.
There are two very big mistakes that dog owners make, (1) they don't keep the dog socialized weekly to people or other animals (2) They stop training on a daily basis because the dog may have already learned the basic commands. But then they want the dog to be just as well behaved in a social situation and that's not gonna happen if you don't keep up with it.
I am going to direct you to a training site since you are already using treats and this will show you how to teach commands and mark the behaviors you actually want to see.
clicker lessons
http://www.clickerlessons.com/
video http://www.clickertrainusa.com/clicker-training-videos.htm
dog training consultant
24 years training & behavior,pet first aide, Therapy dog eval., PA Animal Response Team
Thank you Nicole for that information. At the age of 7 months when he went after the child was he neutered at that time? What was the child doing at the time? When he went after the child what did you do?
What do you do now when the dog?
Thank you for that information. That is a concern that there is no warning as there is something called rage syndrome which used to be thought to be more exclusive to spaniels, but they are finding it in other breeds so I will direct you to a site for this for further reading just in case.
If he was fed when he was growling /barking etc. at someone then he sees that as a reward for that behavior and although I know you were trying to take his attention off of the person and put it on you it may have been done at the precise time he got it mentally that he needed to bark/growl at someone so in essence you could have been reinforcing that behavior. What I suggest along with the clicker lessons is that you put him on the nothing in life is free diet so that further puts you at the top and the one he wants to listen to whenever you give a command. It may mean starting off slowly and at the beginning again and taking him near a park but safely far enough away so that he does not get worked up at seeing people/animals and you can reward him for the good behavior, then gradually moving him closer to the area over time and as long as he starts associating people/animals and his good behavior as the right way to act and be rewarded for.
Here is more on the nothing in life is free diet.
Nothing in life is free
http://www.winnipeghumanesociety.ca/yelp_Line/dogs/nothing_free.php
NILF being the leader
http://siriusdog.com/articles/kids-dogs-bites-safety-prey.htm
clicker training for barking and lunging (and other information)
Rage syndrome: This problem has also been reported in American Cocker Spaniels, Bernese Mountain Dogs, Chesapeake Bay Retrievers, Dobermanns, English Bull Terriers, English Springer Spaniels, German Shepherds, Golden Retrievers, Pyrenean Mountain Dogs and St. Bernards.
http://www.cockerspanielrage.org.uk/whatisrage.htm
http://www.petbehaviourcentre.com/articles/a_clicker.htm
rage or epilepsy? http://www.geocities.com/Heartland/Meadows/8195/tle.html