I've been looking at South African mastiffs... seems like they weren't so inbred. They took mastiffs from England in the 17th century I guess and used them to protect against Lions etc. So only the strong survived. I saw some pups that actually had white markings, which is something that used to exist in english mastiff lines but has been lost through inbreeding.
Anyone have experience with them? They're supposed to be pretty healthy. I know they're gonna be a good guard dog. Just wondering about how they do with other dogs etc.