My Yorkie also chases the cat, but in my case it is more play than terrorizing.
When Sophie Kate was a puppy she would attempt to be "Alpha Dog" over the cats, while I was attempting to train her with the "No" command (sharply saying NO and clapping my hands) the cat took over training, smacked her a few times and it all seemed to stop.
Of course I had to put up with high drama from Sophie Kate because the cat smacked her. I should add I was always aware of the cat being around Sophie Kate at first to make sure the sharp claws did not cause harm.
__________________ Cheryl,Mom to  SophieKate |