Hot Dog is also the name of the cartoon pooch owned by Jughead Jones.
In 1968, Archie and the perpetual teens from Riverdale had their first opportunity at television. The rather flat Filmation series, buoyed by Don Kirschner-produced pop tunes, became a hit. Its versions of the characters would appear in several spin-offs through to the late 70s, and on a series of kiddie-oriented pop albums. The show also established Hot Dog as a member of the gang.
Filmation had specifically requested a dog character be added to Archie's inner circle. We don't know the exact reasoning1, but Archie comics happily introduced the pooch in Pep #224. Communication between the studio and the comic company appears to have been poor, because Hot Dog clearly belongs to Archie in his debut. In the series and in all subsequent comic books, he is definitely Jughead's dog.
Much of the tv show's attempts at humour came from Hot Dog's reflected asides and quips about the teen antics. So important was he to the show that the large white sheep dog often turned up at Riverdale High and stowed away on class trips. His prominence in the comic books varies over time. Like many comic-book and kiddie-media pets, he disappears and reappears as the plot requires.
In 1990, he received a series of his own which lasted five issues. In addition to the predictable doggy adventures, he received a Dilton Doiley-built techno-doghouse and met canine space adventurers, the Astro-Mutts. They awarded him with an even fancier dwelling which, TARDIS-like, was bigger within than without. Like the existence of spell-casting witches and superhero Archie alter-egos, these fantastic matters have no impact on the more typical Riverdale stories.
Hot Dog has survived and, while he never proved as popular as Snoopy or Scooby-Doo, he has managed to be more than a Poochie.
1. Scooby-doo, which premiered the following year, had been pitched as a show about mystery-solving teens, and only in development did the cowardly great dane take center stage. Clearly, someone thought dogs sold kiddie shows. The inspiration may have been Charles M. Schulz. By the late 60s, Peanuts had developed into a cultural phenomenon. Kids and adults read the strip, intellectuals commented on it, and merchandisers cashed in. Snoopy had grown from a bit-part player to top dog, so far as marketers were concerned, and possibly Archie Comics and Filmation had hopes that Hot Dog would follow the beagle's lead.
"Alternate Universes in Archie Comics." Wikipedia. http://en.wikipedia.org/wiki/Alternate_Universes_in_Archie_Comics
"Did You Know?" Archives, November 2000. Archie Comics Online. http://www.archiecomics.com/acpaco/diduknow/diduknow_november.htm
"Jughead Jones." Wikipedia.http://en.wikipedia.org/wiki/Jughead_Jones
The late 60s Archie Show, which I watched as a kid. I recently saw a few reruns. It's really, really bad.