Rocko and Spunky are watching TV together while eating some "Nothing Wafers". You overhear some talking on the TV and it goes to a commercial. The commercial is for cleaning your dog of parasites and vermin. "So buy: Scum Away Doggie Spray" says the commentator.
Rocko grabs his bottle of Scum Away and sprays Spunky as he wonders what kind of parasites live on his dog. The scene zooms in on Spunky's back and reveals a living room with a lamp, desk, chair and TV. The door opens and a tick enters the room. He takes off his gas mask, complains about how bad the atmosphere is getting and contemplates why he can't just be happy and sit down in his favorite arm scab at the end of the day. A laugh track kicks in. He sits down and grabs his can of "Plasma Cola". Just then a ring worm comes out of the ground/Spunky's skin. The tick and worm both smile as some familiar sitcom music kicks in. (This is a parody of the 60's sitcom, "The Patty Duke Show.") The music introduces these characters as Bloaty The Tick and Squirmy The Ringworm.
After the intro song, Bloaty tells Squirmy that his boss, Mr. Ickk is coming over for dinner tonight. Squirmy claims he is an expert cook and he'll cook up a roast so good his boss will make him a Vice President. The scene then switches back to Spunky sitting on the sofa. He sees a trail of waffers and starts eating them one by one. They lead him up the stairs and in to the bathroom, where Rocko is waiting. He slams the door shut behind Spunky.
Again, the scene switches back to Bloaty and Squirmy. They celebrate Bloaty's guaranteed success at becoming the Vice President by drinking some Dog Sweat. As they drink away, smoke starts to fill the air. They realize that the roast is burning but it's too late to fix it by the time they pull it out. It's ruined and so is Bloaty's chance at becoming Vice President. As it seems that things couldn't get any worse, the doorbell rings. Squirmy, however claims that he can fix the roast while Bloaty talks to his boss, buying Squirmy some precious time. Bloaty answers the door, where Mr. Icck is waiting.
After leading Mr. Icck inside, they decide to have a drink. They stick straws in the ground/Spunky's back and suck away. The scene switches to Spunky as he scratches his back furiously. Rocko is standing over him and is about to give Spunky a brush. Once again the scene brings back to Bloaty and Squirmy's situation. Mr. Icck is sitting in Bloaty's favorite arm scab, as Squirmy hands him some "Fried Lice Fritters". Just then they hear a loud noise and turn around to see a giant brush come crashing down, carrying Mr. Icck away with it. Bloaty and Squirmy run over to Mr. Icck, who is completely dazed and confused. He asks what happened and Squirmy tells him he ate the Lice Fritters and thought they were delicious. He believes every word Squirmy says.
The scene goes to Spunky, who is lying on the floor very comfortably. Rocko finishes brushing Spunky and tells him it's time for a nice, warm bath. Again, we go to Bloaty and Squirmy's house where Mr. Icck is still puzzled. Bloaty tells him to sit down in his favorite arm scab. Just as he's getting comfortable, the ground is flipped upside down and they all fall, just barely catching on to a piece of hair. The scene switches to Spunky, who is clinging on to the ceiling. He really doesn't want a bath. Eventually, the ceiling panel falls. The panel hits the water with Spunky on it, shooting him into Rocko's face, narrowly escaping the water. Rocko gets up and goes after Spunky, who runs up the shower curtains but Rocko pulls these down so that Spunky will come down from there. After many unsuccessful attempts, Rocko finally gets a hold of Spunky and carries him over to the bathtub. Right as he's about to drop Spunky in, the scene brings us back to Bloaty and Squirmy's place.
Bloaty sticks his head in to the ground and keeps talking about he's ruined. His boss will never make him Vice President. Mr. Icck walks up and says he had a great time. He believes he probably loved the food and that the dog sweat was the best he's had in years. He tells him he's found his new Vice President, Squirmy The Ringworm! Bloaty is completely shocked and goes crazy. He jumps on Squirmy and begins to strangle him, just as a wave of water comes crashing down on to both of them. The scene brings us back to Rocko's bathroom, where Spunky and him are all wet, sitting in the bathtub. He pets Spunky on the head right as he gets an itch. He scratches it and the scene zooms in on his back.
We see Bloaty and Squirmy, ship wrecked and laying on a piece of land. (This is a parody of the 60's sitcom, "Gilligan's Island.") Bloaty shakes Squirmy to see if he's dead or not. He isn't and burps water into Bloaty's face, bringing him to rejoice.. Bloaty scratches his back and the scene zooms in on it, revealing another house similar to the one that Bloaty and Squirmy had. The door opens to show an amoeba, who yells to his wife: "Lucy, you got some 'explaining' to do!" (This is a parody of the 60's sitcom, "I Love Lucy.") She cries. After the iris out, Mr. Ickk comes back and tells the viewers they're fired and that the episode is over.
Martin Olson, creator of Bloaty and Squirmy, described the work for Dirty Dog as one of the most memorable moments in the production of Rocko's Modern Life. Olson found Joe Murray's drawn designs of Bloaty and Squirmy to be humorous. Olson said that he and the crew "had tons of fun recording and singing my nutty "Bloaty & Squirmy Theme Song".
The Bloaty and Squirmy Show sequences are parodies of classic television sitcoms, specifically, The Honeymooners, The Patty Duke Show (the theme song), Mary Tyler Moore (the "ya got spunk" routine is parodied), Gilligan's Island (When Bloaty and Squirmy end up on Rocko's skin, Bloaty especially parodies Skipper calling Gilligan "Little buddy") and I Love Lucy (the germs on Bloaty's skin).
This episode is similar to the SpongeBob SquarePants episode "Gary Takes a Bath" except there are no parasites like Bloaty and Squirmy.
Rocko wonders what kind of parasites live on his dog before we first get introduced to Bloaty and Squirmy, implying that they exist solely in his imagination.