My dog is almost 8, and ever since I can remember he has been growly towards dogs during walks. It's weird. Sometimes he's fine if they're far enough away, and we've socialized him with dogs, and he was really good with them.

But when I take him to the dog run (a place where people in the neighborhood can walk their dogs), he gets out of control sometimes when a dog walks toward him. I hold the leash firmly and walk the other direction, but that hasn't worked. Treats do not work AT ALL. I've taken him to growly dog class and he was fine there, probably because it was an enclosed room (he's good in enclosed places). I try to talk to him firmly and calmly.

I've watched "It's Me or the Dog" and "Dog Whisperer", and I try to follow their advice. Sometimes I feel it's different for each dog or that they're techniques are treat-reliant, and, like I said, my dog doesn't respond to treats in the heat of the moment.

Can my dog be trained to behave? Some really understanding dog walkers helped me with him one time. They basically took his leash off and let him walk with their dogs since their dogs are super mellow and won't fight back. At first he was snappy, but he quickly eased up. I feel like if he and the other dog(s) approach each other slowly, he won't feel threatened and won't snap or bark. But it's a lot to ask from other dog walkers and I don't expect them to be compliant.

Any tips/suggestions are welcome. Thanks.
Also, is it possible that my dog can do a total 180, and he'll be friendly with dogs that he meets? Or is the best outcome that he won't bark at dogs so long as they don't get too close?