I am a dog walker and pet sitter. There us a dog I have been walking for 5 yrs. He is a rescue. He has one eye. He was very skittish at first. He was afraid of mail boxes and vehicles. We had actually made a lot of progress the first year. Up until last week, I rarely had any trouble . Since last week, I can't get him out of his crate. The crate is always open. He shakes. I now sit down next to his crate with a treat and he comes out. He has always shied away from the leash. Once it's on, he's ready to go. Lately he tries to go to the room after it's on. On the walks, he cowers when vehicles pass, his hair goes up, he barks, growls, shows teeth and shakes his body and head aggressively. He wont walk alone. He has to have his buddy, another dog. I have worked in this and I can get him 3 houses down. Ive tried different collars, leashes, treats, tone of voice, consulted my books. And nothing has worked. Last week it seems there has been a few steps back. This has happened occasionally, but not for this long. Any help would be appreciated. Thank you .