On the topics of pigs, dogs, and pets; most people don't realize how intelligent and affectionate cows are. Dairy farmers often love their cows more than their dogs. And the farmers that have dairy cows and other cows have this mental barrier where one group is food and the other is family. I bet most people that have eaten a hamburger have never pet a cow.
This is not some meat-is-murder tirade - I'm not even vegetarian. It's just neat to think about the assumptions that construct our worldview.