That may make it sound like it's some kind of cute comedic parody, but the official blurb on Amazon tells otherwise:
“This engrossing manga replaces the human characters who fought and died in the Vietnam War with cute anthropomorphic animals, recreating the conflict with its horrific violence and vivid military exploits intact.”
The series is ongoing in Japan, and while it's licensed, only three volumes have been released in English so far, all in 2004, by ADV. Now, since that was before ADV Manga started running into its real troubles, I'm guessing we can assume that Apocalypse Meow didn't sell very well and we probably won't see new volumes, and the old volumes appear to be long out of stock at bookstores.
But if this unusual title sounds like something you want to read, there ARE used copies available on Amazon.com, and probably other used booksellers. If you actually HAVE read it, leave a comment-- I want to know what you think! Meanwhile, I'm going to look around my local used shops, because this sounds too weird to miss.