I originally read the cook’s line in the opening panel as “I’ve been feeding the men dog for weeks.” This pleased me — not because I advocate dog-eating, but because I advocate the long besieging of the Crock characters in their fort by a murderous enemy, forcing them to eat first their emergency reserves of canned food, then their livestock, then their pets, then each other. If we’re only one step away from cannibalism, then we’re only one step away from the end of Crock.
From the stunned, disbelieving expressions on the faces of Mr. and Mrs. Hitler there, not unlike those of the Wicked Witch of the West’s guards when they realized that their terrible mistress had been liquidated, I’m guessing they’re interpreting “bought it” as a variation of “bought the farm,” and that they are hoping against hope that the hated Marmaduke has expired right there in the middle of this furniture store. This seems like the most likely interpretation of the phrase, as dogs as a rule do not have access to money, and they certainly don’t have access to the kind of money necessary to buy a nice couch. But in fact Marmaduke is an immortal demon-hound and cannot die. He probably just bought the couch with their credit card, which he borrowed from them when they weren’t looking.
I love the carpoolers’ expressions of mingled fear and uncertainty in the final panel here — exactly the expressions you’d expect from people who just heard one of their associates addressed by name by the radio. It’s as if they’re realizing that they exist as minor characters in someone else’s narrative — and that someone else is the irritating guy with the bizarre hair who’s always holding up the car pool.