I have a greyhound. They tend to have prey drives of varying degrees because they were bred as hunters for small, fuzzy things. When greyhounds are adopted out, they are tested for their tolerance of cats and small dogs. Rock has mixed results with dogs, and considers cats to be prey.
Whenever I warn someone of Rock's prey drive because he's going to be in the vicinity of their small creature, I frequently get a very dismissive, "Oh, my pet can handle themselves." It makes me want to shake them and point out it's not a dick waving contest, I genuinely don't want him to decide that the animal in his vicinity needs to go in his mouth.