Hello! I have a 5-year-old goldendoodle, and I need your help!
Context: I have had him since he was a puppy, and from ages 1-3, he was perfectly fine walking around other dogs/going to dog parks. My parents even have 2 dogs and 1 cat at home, and I also have a cat who my dog has no problems with ( unless they get too close, then he snips but never bites). Now, it's like a switch flipped. When we go on walks, he can't even see another dog without losing his mind. He pulls a lot on his harness/leash, but it's the reactiveness that is the real issue. When he sees them, his chest gets bigger, and he starts to bark/growl and wants to lunge; his tail does wag when he does this. He did do training when he was a puppy, but I don't know what to do! Any advice is very welcome, and any additional info I need to give, I'm more than happy to! I just want to help my dog and become more knowledgeable on what I can do.