Don't know....but I bet she's not been participating in any spay or neuter program at all. You'll have to call the ASPCA and get right on it...looks like a feral dog in need of population control.
Moostiff? I know it's not an English Moostiff, perhaps it is a Russian Moostiff (Larisa would know) or maybe a Tibetan Moostiff (I've never seen one before).
It can't be one of those Neopolitan Moostiffs because it is all brown, not vanilla, strawberry and chocolate colored.
Whatever breed, I would certainly suggest heeding the sign.