We are, of course, but a new book on animal cruelty will make your jaw drop about how vicious humans can be to other animals.

Shamu's mother was harpooned.

She was killed in the wild by the crew that captured the first in a series of young orcas that have since been trained to do tricks at San Diego's Sea World marine park, known sequentially as America's most famous performing sea mammals.

And maybe that's all you need to know to realize just how far humans will go. Maybe that's all you need to know - were you beside me on those bleachers, years ago, cheering Shamu? - to see blood, even faded and vestigial, on your hands.

Erin E. Williams and Margo DeMello's Why Animals Matter: The Case for Animal Protection (Prometheus, 2007) is a book so jam-packed with literal crimes against nature that it's hard to read more than a few pages in one go. Williams works for the Humane Society of the United States. DeMello is an administrative director of the House Rabbit Society.

Together they have painstakingly assembled statistics, news reports, anecdotes, and observations exposing the sufferings of so many creatures in so many industries -- food, fashion, entertainment, medicine -- as well as hobbies ranging from hunting to ostensibly positive pet-ownership that you recoil from revelation after revelation about Chinese cat-fur coats, say, or "spent" racehorses that are slaughtered for dogfood. On information overload, you blink: Wait ... my species does that?

Indeed it does.

It hunts over 22 million mourning doves in the US every year.

It rounded up tens of thousands of pet dogs in China in 2006 and slaughtered them in an alleged health campaign.

It gorges on salmon factory-farmed in such overcrowded tanks that their skeletons become malformed and their skullbones burst through their skin in a condition called "death crown."

Imitating rap stars and other fashion icons, it has enthusiastically revived a moribund fur and exotic-animal-skin industry.

It wears the hides of alligators that were either slashed and bled to death or flayed alive.

It indulges in cosmetics tested by the weeks-long application of toxins to the eyes of rabbits locked in stocks.

It bets on battles between fowl drugged with steroids, strychnine and amphetamine and bred specially to tear out each other's eyes, rip each other's flesh and break each other's bones in fight after big-money fight.

It shoots zebras and yaks in Texas.

We tell ourselves that we already know enough about this: at least the basics, all we need to know. Yet just as car accidents don't let you look away, this book's breadth and specificity compels you to linger and learn more, then more again: collecting grisly tidbits to marvel at. To sling later at idiots. To arrange side by side along those moral lines that will shimmer in some future sand as you wonder which shampoo to use, which clothing brands to buy or what to eat.

This is the rest of the tour that Eric Schlosser began in Fast Food Nation - paced not quite at a bovine plod but still deliberately, somberly slow - of that bustling, bloody world-within-a-world in which terrible things happen to animals. The evidence is everywhere: in the bedroom closet, the medicine cabinet, the fridge, the restaurant, the cupboard full of cleansers under the sink. It's at the pet shop, circus, zoo, aquarium, boutique. Even if you're a pleather-clad vegan sitting perfectly still in an open field, you are implicated - used - as an ostensible statistic, who by virtue of belonging to Homo sapiens can still be considered a potential eventual customer for countless cosmetics, comestibles, clothes, drugs and other future products whose marketing schemes are already under way. The macular degeneration, diabetes or fondness for fur-trimmed jackets that you might or might not someday develop is reason enough for wealthy powerful companies to justify inflicting untold things on untold creatures: "Even with all of our laws," Williams and DeMello muse, "and even with a nation of caring people, we still tolerate - and many of us unwittingly participate in - an unprecedented degree of animal cruelty. How can this be so?

"Perhaps the biggest reason why society tolerates routine abuse of animals is that for the most part, these abuses are hidden."

It's as if a huge mill is in perpetual motion, grinding away behind the scenes, a constant stream of creatures being fed nonstop into its maw.

Rather than "engage in complicated philosophical arguments," the authors stake a claim instead on our "common sense and common decency":

"While we can purchase cheaper meat from animals who never experienced sun or air," they venture (and by using the pronoun "who" in reference to nonhumans they make a deliberate political choice), "while we can buy virtually any animal we want as a pet, while scientists can create mice with human genes and even with human tissue, and while rich hunters can pay thousands of dollars to shoot an endangered, tranquilized animal, most of us, if we knew the realities behind those choices, would take a step back and reconsider ... just because we can do all these things, should we?"
Dispensing with analysis, they're all about disgorging details: shock after shock, yuck after yuck, scare after scare in what amounts to a collective elegy for a century-plus' worth of sick, injured and dead animals. Which among the thousands of details in these pages will stick in your mind, as opposed to my mind or that guy's over there, depends Rorschach-like on your personal history, sensitivities and quirks. Because I happen to be a hypochondriac - don't cough anywhere near me on the bus - it's the ailments, human and animal, that I imagine oozing and throbbing long after shutting this book. Fur-farmed minks, for example, are susceptible to gastric lesions, tumors, botulism, diarrhea, cysts and eye disease. Egg-farmed hens get osteoporosis, liver hemorrhagic syndrome, and uterine prolapse, in which the womb distends outside the body. From constant contact with feces, dairy-factory cows get a painful and potentially lethal udder infection called mastitis. Marine mammals confined in concrete tanks tend toward pneumonia, bacterial infections, and abscesses. For pet-industry rabbits, it's reproductive cancers.

When animals "defecate or vomit on the workers" in factory farms, "they can spread diseases such as E. coli, campylobacter, and listeria." In case you're curious, campylobacter causes bleeding gums, oral bone-loss and dysentery. "Factory farm workers are also exposed to infectious diseases such as anthrax, psittacosis, brucellosis, leptospirocis, swine influenza A, and avian influenza A," the authors write.

Good to know. And we can only guess at the pathogenic legacy of industrial accidents such as the 1995 spill that sent 25 million gallons of hog waste into a North Carolina river. For you it might not be the diseases that resonate but rather the photographs, say, or the pain: Fur-farmed foxes are killed, for instance, by having metal rods jammed into their anuses and being induced to bite electrodes. Or it might be the pathos: Hunters collecting live specimens for early zoos, for example, "boasted in excruciating detail of ... the baby animals who mourned at the sides of their dead mothers until they were snatched away, put into cages or tied or chained up, and transported to Europe. Because most social animals like gorillas, chimpanzees, elephants and hippos guard their young, collectors had to kill the adults (sometimes the females, but often the entire herd) when capturing their babies." This is no longer standard practice, although it's too late for Shamu's mother and the rest.

Or it might be the sheer numbers that get you: over 3.8 million kangaroos killed for their skins every year in Australia. Some 265,000 rabbits and 65,000 dogs used in US laboratories in 2004 alone for toxicity tests, medical-school surgery instruction, dental and heart experiments and more. Sixty billion pounds of sea animals killed and discarded annually by industrial fishing operations worldwide as "bycatch" after being caught in deepwater trawls and purse seines set out for other species. Tens of thousands of dolphins at a time corralled into coves and slaughtered en masse for their meat during Japanese "dolphin drives." Tens of thousands of pet dogs seized from their owners and clubbed, hanged and shot during that 2006 anti-rabies campaign staged by the Chinese government. Thirty-five thousand miles of US rivers in 22 states and groundwater in seventeen states contaminated by factory-farm runoff, according to the EPA.

At the end of each chapter, the authors offer helpful, practical pointers. Report poachers, they suggest. Buy a vegetarian cookbook. Watch animal-friendly TV shows such as Animal Cops and Emergency Vets. Spay or neuter your pet. Buy cruelty-free products. Vote. These tips are peaceful little polyps in what is otherwise an unflinching indictment of human appetites, of our ridiculous desires. It's an indictment of our behaviors and ourselves. They are not named in this book, but it is flesh-and-blood individuals - mothers and fathers, sons and daughters, friends, husbands and wives - who flay those live 'gators. And who insist, via groups such as the National Alternative Pet Association, that they are entitled to own skunks, wallabies, hedgehogs, and exotic cats, even to buy tiger cubs online for a few thousand bucks each.

It is mothers and fathers, husbands and wives who Internet-hunt, paying to really shoot real animals in real time via a gun and webcam connected via remote control to their computer mice. And somebody loves them.