Absolutely dogs will kill cats. I have 8 cats, 18 dogs. One of those dogs thinks that cats are tasty little snacks. I've done everything possible to train Kayleigh not to eat cats with NO success at all. Her prey drive is so high that almost anything smaller than her is prey--she's a 120 pound mal-mix so most things are smaller than her! Kayleigh can not be safely around a cat in any situation. When she comes inside, my cats get locked up. I've told my neighbors that if their cats end up on my property and Kayleigh kills them, I won't take responsibilty for that. If she gets loose and kills a cat, that's my fault!

Some breeds are more prone to small animal aggression than others. Huskies and other Northern breeds are notoriously bad with cats. I've been lucky that the vast majority of mine have learned to leave my cats alone. For some of them it's taken a great deal of work and training to make them cat tolerant. Mainly I think because my cats are indoor only. The dogs see them as house animals only. I would not guarentee the safety even of my own cats if they were loose outside.

I'd never leave a dog, even a proven cat-friendly one, alone with my cats. I've heard too many horror stories of dual pet owners coming home to dead cats.