My dog is two years old, and he's like really energetic because everytime he sees someone he jumps on them. He hardly even likes to wear a collar, and when i tried to put him on a leash, he tugs it and stays in one place so i can't take him any further. One time i tried to walk him, and he went ballistic. He started running around and going to every tree on the street to pee. I tried to pull him back, and the collar slipped off his neck and it was really hard to catch him. I sooo regret i didn't train him since he was a puppy. I was thinking of buying him a dog harness so it wouldn't slip off his neck again. Is there any other chance to teach him to walk by leash? Or do I need to hire a dog trainer? Thanks alot!!