Clearly you do not own cats.

Are you talking those cute furry four legged sadistic serial killers?

Hot damn I don't. I always thought I'd be a cat person but sounds like I need to revisit my choices!

Not for more intelligent animals. Consider the footage of killer whales "playing with their food" from Blue Planet.

I have seen California sea lions killing ocean sunfish (mola molas) in a way that appears to be sadistic, or at least just for sport. The sea lions bite the fishes' fins off without eating them, then play with the crippled bodies like living frisbees. After a while the sea lions get bored and let the fish sink to the seafloor where they're eaten alive by crabs.

Nature, red in tooth and claw.

Is that a form of sadism? Perhaps the sea lion is unable to conceive of the suffering of the fish. To the sea lion, the fish is merely an object. Playing with the fish is no different than playing with a rock to the sea lion.

Does that matter for the fish?

No, but that's not the question being discussed.

Sounds very similar to a psychopath incapable of empathy.

Lack of empathy is the norm in nature, not the exception. A species of predator that could empathize with its prey would starve to death.

Yeah, my point was that the GP probably wouldn't view a psychopath as innocent as a sea lion, hence there would seem to be a double standard.