The Official Cat Codependents Handbook: For People Who Love Their Cats Too Much, by Ronnie Sellers (TPB, 1995, $2.25)
(Hello, Julia!) It all started when a customer asked Sellers to autograph a whole lot of books... each for one of her cats! This led to Sellers' writing about extreme cat lovers, which led to lots of mail in her mailbox. It would appear the letters here are really real. (And the illustrations by Jennifer Reinhardt are wonderful!)
Look for this book in the pet section, avail. 12/21.