Uncertain. I havent seen any official logo ever. This is the original logo/icon from back in 2013 though, probably the closest youll get to official (it might actually be official Im not entirely sure):
/cdn.vox-cdn.com/assets/3727699/Dogecoin_logo.png){kind=logo}
I have found an unofficial doge-sans font today too, looks pretty good so I'll likely use it!