presa canario / cane corso fuckin beautiful dogs, and not well known, so haven't been fucked up with ridiculous cross/in breeding like pitbulls...shame. If you have a dog for protection it is also a consideration to crop the ears and tail because no matter how aggressive/protective a strong breed is, if they clamp on you, they will release if you pull them hard by the tail or ears...so it's kind of like cutting away the vulnerable points.
http://www.showstopperkennels.com/showstopperkennels.com/index.htm