This news article is a little late in posting but I thought I'd share it anyway. There's an 18 month old Golden Retriever who protected his young owner (11 year old boy, Austin) from being attacked by a cougar.
(I'm talking about the four legged, furry kind with pointy teeth ... not the two legged, scantily clad kind in stilettos.)
Born to be a hero: Why Angel saved the day
Check out the above link, it's pretty neat. They had Stanley Coren analyze the act after the fact and this news article explains his take on it. It's a pretty interesting article.