Uhm, the cat was most likely just cleaning its tongue off on the owl. They lick all kinds of stuff that way, including couches and people's pants. Either that or it was trying to figure out if the owl would taste good. It's easy to impose our own perspective on things like that.
Now, dogs, on the other hand, they do seem to have affection and loyalty. Some cats do as well, but they're in the minority. Most cats are just cold users. It's very common for dogs to give their lives protecting their masters. Or you see the dogs that get depressed when their masters die. We have a dog that's gotten attached to my oldest daughter. When this daughter goes to school, the dog sits there by the door looking depressed for much of the day.