Why CatDog Is Darker Than You Think

A funny thing happens when you decide to go back and watch your favorite childhood cartoons. You realize just how messed up many of them were. 

Rewatching the likes of "The Ren & Stimpy Show" and "Rocko's Modern Life" will unveil a plethora of dark jokes. "Ed, Edd N Eddy" had no problem with including dirty humor, especially when the friends decided to hide under Eddy's bed. This humor made the shows enjoyable for the parents of children to watch, so they wouldn't mind sitting down with their youngsters to view them. However, if there's one show that had no problem with putting its dark nature on full display, it's "CatDog."

The series ran from 1998 to 2005, managing to find numerous comical situations to place the dog-cat hybrid at the show's center in. Cat and Dog may share the same body, but their personalities couldn't be more different, which often leads to many of the mishaps they find themselves in. Already, many unanswered questions arise, such as how these two manage to go to the bathroom. That question's easy enough to put out of your mind while you're watching the show, but there's a darker underbelly to this show that's harder to overlook.

Cat and Dog have separate immune systems

CatDog may be half-cat and half-dog, but you would assume they would be a wholly unique entity. Rather than falling within either a canine or feline designation, CatDog should be its own creature. But that may not be entirely the case.

In Season 2's "Sneezie Dog," Dog develops allergies, believing Cat causes them. By the end of the episode, we find out he's actually allergic to Winslow, but it brings up an important point. Dog was the one with a runny nose throughout the episode, while Cat was perfectly healthy. This episode implies that even though the two of them have the same body, they have separate immune systems. If true, it would result in many medical challenges down the road.

Another example of this can be found when Dog eats numerous pecan pies and develops pecanitis in Season 1's "Dog's Strange Condition." Again, only Dog is affected, although Cat grows a tree out of his head by the episode's end. It's a strange incident because the symptoms should've affected them equally, but it suggests their organs are entirely separate entities from one another. It's a dangerous situation for the two because one of their immune systems could easily detect the other as a threat. It's what happens during transplant rejections for humans when foreign tissue or organs go into a body that can't medically accept them.

For all we know, CatDog's body could be slowly trying to kill the "foreign" entity, and that brings up the most disturbing question of all. If one dies, would the other be forced to drag around its corpse until it passes away, too? On second thought, maybe it's best not to think too deeply about all of this.