So we've been having issues with Diego. He is almost 2 yrs old in June and has recently been exhibiting fear based aggression towards humans! It's scaring me to death now that it has turned to people. He has always been very timid with strangers since he was a puppy. He's very protective of the house and "his" street and has been somewhat leash aggressive towards dogs within past 6 months. Usually he just gets scared of some people and tucks his tail, bows his head or jumps back (but not to everyone).

The other day, the neighborhood suddenly appeared from around the corner and was walking towards us quickly. It set Diego instantly on guard but I was trying not to choke up on his collar to make him even more heightened. Then the neighbor slowed down and put his hand out to his face, while I was trying to tell him not to do that. Diego did not like that and lunged at him barking and showing major teeth action. The neighbor just kept walking away while I scolded the dog. I later went over to apologize since I was so embarrased. He was totally "okay" with it and laughed it off. I didn't find it quite so amuzing and called a trainer immediately to come over this weekend and help with his behavior before it escalates.

One of the first things "David the Dog Trainer" said was we need to immediately stop using a pronged collar and start with a Gentle Leader or Haltee sp?

I'd love to know any ideas, tips, suggestions from other big dog owners who have exprienced similar situations with their big dogs. FYI: Diego is an 85lb lab/american bull dog mix.