The first question that came to my mind: where did they get a feline floatation device? Is there a store somewhere (in Portland, Oregon, maybe?) called "Aqua Cats: Your Purr-fect One-Stop Shop for Feline Water Sports!"?
I, too, understand the scourge of feline obesity. As the owner of two very fat (but now, after endless effort, slightly less-fat) cats, we still nasty looks from the vet, who seems to think that we are funneling food down their gullets, perhaps preparing to eat their livers on a cracker someday. As delicious as that sounds, it is not, in fact, the case. However, I'm yet to take my cats swimming. Not because it wouldn't be hilarious, but because Francis and Seymour would turn it into a revenge plot to rival the third act of virtually any Quentin Tarantino film.
It's obvious that the swimming cat is thinking of nothing but exacting justice. Killing the people responsible in their sleep would be FAR too easy. This cat is gonna be slick about it. Holly's owner/s, be warned! She's going to go online and ruin your credit report by opening high-interest credit cards in their name and buy a Real Girl and 20 cases of giant dildoes and have them delivered your place of business. Then, she's going to go on a lot of deeply weird pr0n sites and hit "Like" on Facebook, while signed in to your account (which raises the question of why they have "Like" buttons on porn sites, but that is beside the point).
Then, she's gonna click "Yes! I would like a representative from the Tabernacle of Holy Rolling to make a personal visit to my house for an in-depth discussion of my personal relationship to Jesus Christ!" on the websites of multiple non-mainstream churches, and put you on the mailing list of various religions loosely based on short stories about spaceships.
And if your car gets a boot on it, well, you won't have to wonder why...