The strip is focused on the antics of a
human male,
Mel, and his male
canine companion,
Fergus. The lines between master and companion are extremely blurred: Fergus frequently asserts his rights as equal, or perhaps superior, partner in the friendship. In an early strip, Mel labors for three panels to install a
pet door, only to have Fergus stroll in via the doorknob. Of course, this works both ways; several strips later, Mel flounders with his order at a fancy
restaurant, only to be saved by Fergus, who orders for both of them in fluent
French. All in all, Mel and Fergus's friendship is similar to that of the title characters in
Calvin and Hobbes, sharing both adventures and frequent arguments about the silliest topics. Animals in
Citizen Dog can talk, and most of them (particularly dogs and cats) walk upright, chatting with each other and their owners. Furthermore, many dogs look similar to their owners: a slender, bookish man may find his eyewear paralleled on his
dachshund. Almost all characters feature O'Hare's distinctive large nose and
candy corn-shaped body, even the women—with the sole exception of occasional nubile females, who are rendered with large bosoms and caricatured
hourglass figures. •
Mel – The primary human in the series, completely average and unremarkable in every way. He is "
suburbia" incarnate, often content to sit and watch TV for long hours at a time and working a middle-class desk job for an undistinguished company. He has an unusually large nose, likened at one point to a
casaba melon, and rarely ever attracts attention from the opposite gender. •
Fergus – Mel's dog who is arguably the more intelligent of the two, although this also leads to a massive ego. He and the other canines of the strip make frequent observations about the state of affairs in human society and how silly it is.
Technology alternates between boring and scaring him. •
Arlo – Another dog and Fergus's best friend, rarely ever seen on his own, so it can be said that he is strictly a follower and "yes-man" for Fergus. •
Cuddles – The voice of reason in a dog's world, Cuddles is a cat who enjoys fine dining and reading
Jane Austen novels. He frequently gets fed up with Fergus's unenthusiastic attitude to life, and has a well-known hatred of winter ("SAY NO 2 SNO!" is written on a button he tries to give to various people). Often uses baby-talk when conversing with his owner, an unnamed little old lady. •
Bruno – A large, strong sheepdog who never speaks and is often depicted as being rather scruffy. He harbors a friendship with Cuddles which would be considered highly out-of-place by "regular" people, but is accepted as normal in the comic when others see him with the unfortunate cat hugged up under his armpit. •
Mario – A fish who Mel often spends time trying to catch in later strips, but who he usually ends up discussing current events with. Almost landed a part in
Free Willy, but was denied the role for being a trout. •
Maggie – A dark-haired little girl who Fergus and Arlo follow to and from school, amusing them with her tales of what she has to study in
elementary school. She dislikes this attention intensely, especially after Fergus accidentally eats her homework on one occasion. == Collections ==