" The suffering of abused pets amounts to a tiny fraction of the suffering we inflict on animals. In 2012 there were 164 million owned dogs and cats in the United States.2 The majority of them probably live reasonably good lives, but even if every single one of them were abused, this number would be dwarfed by the 9.1 billion animals annually raised and slaughtered for food in the United States.3 Factory-farmed animals have to endure a lifetime of suffering much more severe than the typical dog or cat, and in the United States there are fifty-five times as many factory-farmed animals as there are dogs and cats. Anyone who kept a dog confined in the way that breeding sows are frequently confined in factory farms—in crates so small they cannot even turn around or walk a single step—would be liable to prosecution for cruelty. In The Animal Activists’ Handbook Matt Ball and Bruce Friedrich make a startling claim that vividly illustrates the vastly greater suffering of animals raised for food compared to other ways in which we cause animals to suffer: “Every year, hundreds of millions of animals—many times more than the total number killed for fur, housed in shelters, and locked in laboratories combined—don’t even make it to slaughter. They actually suffer to death. "

― Peter Singer , The Most Good You Can Do: How Effective Altruism Is Changing Ideas About Living Ethically