I got one of those! My Great Pyrenees is amazing. She has a wonky leg and is afraid of the dark, but she is really awesome and gentle with our (indoor) cats. Our cats really love her. Even with her leg issue she is the alpha of our pack, and she's the sweetest baby girl.
Guardian dogs like maremmas are great but you need to be breeding them as well to replace the ones that get killed, especially if you live in a country with wolves and lions. You can get defensive collars for them but unfortunately there's not much you can do to stop them being bitten by snakes.