This isn't as immediately delightful as a lot of Sedaris' other stuff. If you mostly love him for Me Talk Pretty One Day, or Dress Your Family etc etc - ie, the stuff about himself and his family - you may find yourself a bit put off. If, however, you think that Barrel Fever is one of his best works, then you're probably in good shape. Because this lacks the affectionate, albeit snarky, warmth of the other books, and to my mind, much of the humor as well. It's pretty astonishingly grim. The fact that it's about animals exacerbates this effect; not least because they are, for the most part, so horrifically repugnant in their behavior.
But the book also has a lot of really poignant observations about the world. Not in the touchy-feely sort of way, more in the David-Foster-Wallace-irremediably-depressing kind of way. This is where the use of animals is key - I honestly think the book might just be too devastating if it was about people.
The use of animals is, ultimately, what's made the book stick with me (I finished it a few days ago). The thing is, the fact that it's animals he's writing about initially seems kind of gimmicky or pointless, but then you realize how much less palpable these stories would be if they were about humans, and then you start thinking, but wait, I mean, aren't they basically about humans? And it gets you into this kind of interesting contemplation of the human-animal divide and how it relates to literary representation. Is it the "animal" side of the characters that makes them so horrifically brutal, or is that actually the most human thing about them? I mean, only the most extreme kind of human would actually pluck out someone else's eyes, but on the other hand, the appallingly narcissistic behavior of some of the creatures is in some ways more brutal, and is definitely more human. Probably, you'll say I'm overthinking all this, and maybe I am, but in any case, it redeemed the book for me in a major way, because otherwise, I think I might've been too traumatized by the whole thing.