When we adopted Luigi, he was presented as a pit bull, but his surrender form listed him as mom, castillo bred apbt, dad 1/2 pit bull 1/2 english mastif. I assumed it was all nonsese, people who buy and then surrender puppies are assholes and generally full of it..... that said, as Luigi aproaches 3 he seems more and more mastify.... maybe it's true? He is also big for a pit mix, 78 pounds, and has more stretchy neck skin... thinkinking i need to learn more about mastifs