I've been bitten a few times by dogs and most of those bites were from Chows. I despise and have learned to keep my distance from that breed. The blacker the tongue, the blacker the heart.

In the US, at least, you have a significant portion of the population with a puritanical bent. To top it off, they're extremely vocal, political, and organized.

Right or wrong, advertisers are terrified of angering these people.