My dog is a fear biter. I need to know if I should use an electric collar to train him to come when called.

I know you are extremely busy, but you are the acknowledged dog expert from so many different circles, and I am running out of ideas on what to do with my dog, so forgive me for taking your time... I adopted a rott/shep mix when he was 6 mo old, and have had him for a year and a half. As you have probably already guessed, he is a fear biter. We have been to several different trainers, and he is somewhat more comfortable around children after our follow up trips to the park, but he is still snappy/growly to adults both in my home and outside. There is a field across the street where I let him off to run, and 90% of the time things are fine -- he comes when I call, and his on-leash obedience is acceptable, but sometimes there are other people there, and he will run up to them, growl and circle them. I don't want to take away his exercise, but I don't want him to bite anyone either... I noticed that you tell people fear biters can only be handled with strict obedience, and I also noticed that you sell electric collars on your site. Do you think it is a bad idea to resort to an electric collar so he can run, but if he gets too close to a stranger I can correct him from afar? Will that just teach him to associate strangers with negative punishment?

Also, I have a younger 8 mo. GSD (actually a puppy from one of your bitches, Fritzi) who is sound, but someone told me he will learn those bad habits from my older dog, is that true?

Also, for off-leash obedience, what do you think of using the electric collars for both dogs?

Sincerely
Christine