The Canadian A&W hot dog split and served with processed cheese, bacon, and relish is the Whistle Dog.
The Whistle Dog was a signature Canadian A&W menu item. Unlike a plain hot dog, it is split open and dressed with processed cheese, bacon, and relish, giving it a richer, more layered profile. The name belongs to A&W Canada’s menu tradition, not to the unrelated American A&W chain.
The item has had an on-and-off history. A&W Canada discontinued it around the end of 2016, then brought it back for limited-time promotions, including a nationwide return in 2022. That changing availability can make the answer seem unfamiliar, but “Whistle Dog” remains the canonical product name.