One Nation Under Dog
http://www.hbo.com/#/documentaries/o...GyMQIAUKwXOA==
It's about the dark side of human/dog relations. There's a part about 40 minutes into the movie that has fucked me up for life. I'll never be able to get the sounds out of my head.
If you have HBO, check it out. It's a tough watch, but it should be required viewing for anyone who thinks letting dogs breed like crazy is no big deal.