Hi!

I rescued a young German shepherd/Doberman (or Rott?? shepherd shape,
dobie/rott coloring) back in June. At the time of the rescue, he was 12-15
months old, very timid, and deathly afraid of men. He was however, very
well trained, completely housebroken, and great with most kids. I have
spent the last 6 months taking him with me just about everywhere, and
socializing him every chance I get. He has been given love, attention,
security, and affection. He is much more outgoing now, friendly, and will
approach men, although he is still a bit hesitant.

The Problem?

He has an incredibly aggressive response to cats. If there is a
neighborhood cat walking around, he will go after it in a heartbeat. I
watched him chase a cat 25 ft up a half fallen tree a few weeks ago. I have
tried to introduce him slowly and in controlled circumstances to our
housecats
(who have taken up permanent residence in the basement rafters.....) If I
sit in the basement with him on his lead, he will watch the cats very
intently (almost quivering) . If he is off lead, he will run them to ground
and go for the kill. (He actually got one of my mom's barncats earlier this
summer) What can I do to stop this behavior? He was an abused dog, so I
generally avoid punitive methods, but I am out of ideas. He will also
occasionally go after 1 or 2 of my son's friends. Most kids he adores.....
however, there are a few that he will stalk and nip(no rhyme or reason that
I can figure out).

Does anyone have any suggestions/ideas/theories?

Thanks!!

Katie