It depends on the breed of dog because I have been around dachshunds for my whole life and they are usually aggressive around other dogs in my house even though they were trained. They also can't control themselves when they see another species (example: cats). But for cats, the breed doesn't matter. I've never got attacked by a cat or heard a hiss irl. All of the cats I've met were nice and always purred when I was around. On March 18, 2024, a brown tabby jumped in my backyard and when I petted her, she started purring very loudly but my dog chased her out of the backyard. A few months later, that same cat was following me.