We have a 3 1/2-year-old female peekapoo and a 2 1/2-year-old male German Shepherd, both neutered. (Also a very old female cocker spaniel, neutered, but she's probably not directly involved in this issue.)
They're both generally good dogs though not well enough trained and they seem to enjoy the shelter at home time. They also, generally, get along fine.
The German Shepherd's main behavioral issue is that when he gets bored he becomes an insufferable pest. But, that's not my problem here. The problem is that, sometimes, often for no reason I can see, he attacks the peekapoo. He grabs her by the neck tight enough that she has trouble barking. He's never actually hurt her, though he certainly could. There's usually no obvious cause. For instance the peekapoo will chase the German Shepherd away from her food and he's fine with that. She'll eat his dog food, and he's fine with that too. Most recently she was maybe 50 ft away from him peeing in the grass and he ran over and grabbed her by the neck. He's not well enough trained to listen when he is really intent on something like this, so we can't just tell him to drop or come or leave it. He still thinks of commands as strong suggestions. We're working on that. Sometimes he bites the peekapoo when she is barking annoyingly at deer in the backyard. Maybe he can tell that it's bugging me. But him attacking her while she was peeing in the grass stretches the idea that he's being an enforcer for me. He has heard me scold her for peeing in the house, but I like her to pee in the grass!
The peekapoo, by the way, is not intimidated. She stands her ground.
Another thing. They usually get along fine. Sometimes you'll find them curled up on the same mat, asleep.
My questions are, why do you think he's doing this, and what is the most effective way to get him to stop?
