Could use a little help with this Problem.

[-Ruger-]

We just rescued a 11 Month old German Shepherd he is now 1 year
old since his birthday was on the 16th. He is a very good well behaved dog.
He knows the Word "no" very well and "Sit" and "stay". But we recently
took him up to a Dog Lake, and a couple of things he did
alarmed me, He started barking Rapidly at other dogs (We had him On Leash)
and was lunging at them, now I know he is not dog aggressive because I let
him play with about 40 dogs at my work cause it is a Open play facility. I
don't know why he is doing this when we take him up the canyon. He also
did this in Petsmart by barking at other dogs and wouldn't stop. He never
took his eyes off them, and he is not very great on the leash. I don't want to correct him when he is barking at other dogs cause then he will think he is in trouble and its the other dogs fault thus making it worse. Do you have any advice? I want to eventually have him Off leash hiking etc like all the other dogs, butwith this dog problem I am not sure I can trust him at this time.
Any feedback is appreciated.

[sagelfn]

In the last training class I took there was a bull terrier working on his leash reactivity. The dog goes to daycare and plays with many dogs without problem. When he is on leash or when other dogs are on leash he is barking lunging growling.

I would search for a reactive dog class near you. Have an evaluation with the trainers and see what they think.

[APCURLS]

We are working with our rescue (18 months old male) on similar issues. He whines and pulls towards other dogs. I've read a lot on here about redirecting focus. Have you tried bringing treats with you and doing a sit / stay while the other dogs are around? My Draco doesn't seem to care about treats as much as his squeeky ball when other dogs are around, so if he has a favorite toy maybe bring that?

Do you think it's aggressive or curiosity?

Definitely go to training class. We will start with our trainer on Saturday. Good luck and thanks for rescuing!