As part of its ongoing efforts to promote every single Pokémon out there, The Pokémon Company has shared special content dedicated to Growlithe:
Did you know? While it’s quite friendly toward humans once it’s grown used to them, in the wild it must be quite fierce to defend its territory from Rockruff. It has lived alongside humans since ages ago. Its bones have been found in excavations of ruins from the Stone Age.
Source: The Pokémon Company
Source:Pokémon