Yes, there are such things as longhaired mastiffs. No, they are not Tibetan Mastiffs nor Pyr sheps/mastiffs. They are your regular mastiff, with the gene for longer fur. This is similar to the shorter haired Golden Retriever and the longer haired Whippet. They are not a product of irresponsible breeding (as I used to think), but can crop up in many fantastically bred litters. A member on another board had a wonderful website. It is Fluffy Mastiff

Enjoy!