Should be an interesting episode of the Dog Whisperer tonight on the National Geographic Channel: Cesar Milan goes undercover at a California puppy mill and gets a firsthand look at the living conditions the dogs at these mills must endure.

Many of these dogs have never had any interactions with humans–most have never even left their cages.

Here’s an intense little video clip from tonight’s episode. This is actually a legal puppy mill, but the fact that dogs bunched in cages together like this is considered “up to code” according to current laws is pretty frustrating.