Martha wants to play fetch with Helen, but the latter's ankle is injured. Carolina enters, and Helen reveals that the injury is a sprain and it happened in gym class. Carolina reveals that the two cousins are to have a sleepover, then she discovers a note that says, "Remember to take Martha to the vet". Martha doesn't want to go to the vet for her shots, but Carolina takes her anyway.
On the way, Carolina struggles to get a squirmy Martha leashed, then Martha tries to avoid getting her shot, and on the way back, she insists on sniffing everything, to Carolina's chagrin. The two argue over whether Martha's "business" is important, then Martha says that Carolina should see what being a dog is like. A thunderstorm happens and they rush home. By then, it's bedtime, so they go to bed, but Helen is groaning and Carolina is having sneezing fits.
The next morning, Carolina's sneezing fits have subsided, but she's now a collie. Helen doesn't recognise her, but Martha can translate her barks and reveals that she claims to be Carolina. Martha doesn't believe her, and asks whether she thinks dogs should be on leashes. When she affirms, Martha accepts that this is Carolina.
Truman comes over and examines Carolina, along with T.D., who watches. Truman finds Carolina healthy but doesn't know how to switch her back. He then suggests that they determine what turned her into a dog. T.D. wonders if Carolina is a were-dog, but Truman discounts that possibility as there was no full moon the previous night. T.D. then wonders if Carolina and a dog switched bodies. Then, Carolina is revealed to have fleas.
The two female dogs smell trash and go outside. Martha tries to convince Carolina to dig through the trash and chase squirrels, but Carolina thinks they're too undignified. Martha convinces Carolina to eat trash, then the kids show up and scold the two. Carolina claims she understands dogs more and starts chasing a squirrel.
The kids and Martha run after Carolina, who then sees Jorge driving. She runs up to him and confronts him outside the grocery store, but he doesn't recognise her, then Kazuo drives up. The kids and Martha run into Jorge and tell him what happened, then he agrees to search.
Martha realises that Carolina may be in the pound because she has no tags, so Martha tells Kazuo about the situation. However, he doesn't want to let her out since he claims all his dogs think they're human. Martha asks if she can adopt Carolina, but adopting one's own kind is prohibited. Jorge and the kids arrive and Kazuo lets Jorge take Carolina home.
Martha is about to ask the viewers if they got all the vocabulary words, but Truman berates her for ending the episode early, so we then cut to the real ending: Carolina wakes up and it's all a dream.
This episode provides examples of
- Afraid of Doctors: Martha does not want to go to the vet.
- Afraid of Needles: Martha is none too keen on the idea of getting her shots and stammers when the vet takes the needle out.
- Alliterative Title: Dog Daze.
- All Just a Dream: The episode turns out to have been Carolina's dream.
- Animorphism: Carolina turns into a collie dog within the dream.
- Catch Your Death of Cold: Zigzagged — Carolina comes home from the rain sneezing, but she has no other symptoms and is fine the next day, so it's unclear if it's this trope or Freeze Sneeze.
- Cue the Rain: It starts raining when Martha and Carolina are already in a bad mood.
- Death Glare: When Martha says that it's unfortunate that Carolina's not a dog, Carolina glares at her.
- Dogs Hate Squirrels:
- Martha chases a squirrel (right after denying she'd ever run off, no less).
- T.D. imagines the dog in Carolina's body chasing a squirrel.
- When Carolina as a dog sees a squirrel, she's annoyed by it but she doesn't want to chase it. Martha thinks that Carolina should chase it as that's what dogs do, so later she does chase it.
- Later, she's seen chasing another one.
- Esoteric Happy Ending: In-Universe — Martha thinks there's nothing wrong with the episode ending on Carolina being stuck as a dog forever, but Truman begs to differ.
- Faux Horrific: When the boys find out that Carolina has fleas, Truman acts like a doctor telling a patient's acquaintances that the patient has a terminal illness, and T.D. says, "Dun dun dun!".
- Filthy Fun:
- Martha runs in some mud while Carolina is trying to leash her.
- T.D. imagines the dog in Carolina's body rolling in mud.
- During the montage seen after Jorge frees Carolina, she and Martha play in some mud.
- Foreshadowing: The All Just a Dream ending is foreshadowed by Helen's ankle no longer being sprained the alleged morning after the injury occurred.
- "Freaky Friday" Flip: Discussed when T.D. wonders if Carolina is a dog because she switched bodies with one.
- Freeze Sneeze: It's unclear if it's this trope or Catch Your Death of Cold — Carolina sneezes a lot after coming home from the rain.
- Immediate Self-Contradiction: Martha tells Helen that Carolina knows what she's talking about when Carolina tells Helen not to pressure her injured ankle. However, when Carolina says that she'll take Martha to the vet, Martha claims Carolina doesn't know what she's talking about.
- Injured Limb Episode: Downplayed — a minor theme during the waking scenes of the episode is that Helen's ankle is sprained.
- I Resemble That Remark!: Martha is offended at Carolina's assertion that she'd run off... but then immediately chases a squirrel.
- Nervous Tics: Discussed when Carolina gives nervous nail-biting as an example of a "mannerism".
- Offscreen Teleportation: Martha almost escapes from the vet, only for her to immediately appear right in front of her.
- Opinion-Changing Dream: After waking up from her dream, Carolina accepts that Martha doesn't like leashes.
- Our Werebeasts Are Different: Discussed when T.D. thinks maybe Carolina was bitten by a dog/human hybrid under a full moon and became a were-dog.
- Pun-Based Title: The episode is a pun on "dog days" (the middle of summer) and "daze".
- Sneeze Interruption: After coming home from the rain, Carolina sneezes in the middle of her sentences.
- Something Only They Would Say: Martha tests if the collie is Carolina by asking her if she thinks dogs should be on leashes.
- Surprisingly Happy Ending: The episode seems like it will end on Carolina being stuck as a dog forever, but then it turns out to be all a dream instead.
- Urine Trouble: Implied when Martha sniffs a fence and says, "Rinty was here", since the primary way dogs scent-mark is by peeing.
- You Need a Breath Mint: When Truman examines Carolina, he says, "You have bad breath".
