If you buy a Perdue chicken in the grocery store, you might think it had lived a comfortable avian middle-class existence.

“Doing the right thing is things like treating your chickens humanely,” Jim Perdue, the company’s chairman, says in a promotional video. The company’s labels carry a seal of approval from the Department of Agriculture asserting that the bird was “raised cage free,” and sometimes “humanely raised,” although it says it is phasing that one out.

Customers approve. Most of us are meat-eaters who still want animals treated humanely, and one survey found that 85 percent of consumers would prefer to buy chicken with a cage-free “humanely raised” label like Perdue’s.

Enter Craig Watts, 48, a North Carolina farmer who says he raises about 720,000 chickens each year for Perdue. He watched the video of Jim Perdue and had an attack of conscience. “My jaw just dropped,” he said. “It couldn’t get any further from the truth.”

So Watts opened his four chicken barns to show how a Perdue chicken lives. It’s a hellish sight.

Watts invited an animal welfare group, Compassion in World Farming, to document conditions, and it has spent months doing so. The organization has just released the resulting video on its website.

Most shocking is that the bellies of nearly all the chickens have lost their feathers and are raw, angry, red flesh. The entire underside of almost every chicken is a huge, continuous bedsore. As a farmboy who raised small flocks of chickens and geese, I never saw anything like that.

One reason seems to be modern breeding: Chickens are now bred to have huge breasts, and they often end up too heavy for their legs. Poultry Science journal has calculated that if humans grew at the same rate as modern chickens, a human would weigh 660 pounds by the age of eight weeks.

These chickens don’t run around or roost as birds normally do. They stagger a few steps, often on misshapen legs, and then collapse onto the excrement of tens of thousands of previous birds. It is laden with stinging ammonia that seems to eat away at feathers and skin.

I called Perdue to see what the company had to say. Jim Perdue declined to comment, but a company spokeswoman, Julie DeYoung, agreed that undersides of chickens shouldn’t be weeping red. She suggested that the operator was probably mismanaging the chicken house.

That doesn’t go over well with Watts, whose family has owned the farm since the 1700s and says he has been raising chickens for Perdue since 1992, meticulously following its requirements.

As Watts sees it, Perdue realized that consumers were concerned about animal welfare and food safety, and decided to manipulate the public.

The claim about the chickens being raised “cage free” is misleading because birds raised for meat are not in cages. It’s egg-laying chickens that are caged, not the ones we eat. So “cage free” is meaningful for eggs but not for chicken meat. Moreover, Perdue’s chickens are crammed so tightly in barns that they might as well be in cages. Each bird on the Watts farm gets just two-thirds of a square foot.

So why is our government giving its seal of approval to these methods as humane, in ways that seem to mislead consumers?

“U.S.D.A. is the accomplice of Perdue in the fooling of consumers,” says Leah Garces, American director of Compassion in World Farming, who calls it a marketing scam.

Perdue may now be backing away from some of its claims. It settled a suit with the Humane Society of the United States by agreeing to remove the “humanely raised” line from some packaging, even as it denied wrongdoing.

All this leaves millions of Americans, me included, in a bind. We eat meat, yet we want to minimize cruelty to animals. This is an uncertain, inconsistent and perhaps hypocritical path, and it’s hard enough without giant food companies manipulating us . in collusion with our own government.

Garces suggests that such consumers look for labels that say “certified humane”, “global animal partnership” or “animal welfare approved.” But they’re expensive and harder to find.

Perdue’s methods for raising chickens are typical of industrial agriculture. So the conundrum is this. Big Ag has been stunningly successful in producing cheap food . the price of chicken has fallen by three-quarters in real terms since 1930. Yet there are huge external costs, such as antibiotic resistance and water pollution, as well as a routine cruelty that we tolerate only because it is mostly hidden.

Torture a single chicken and you risk arrest. Abuse hundreds of thousands of chickens for their entire lives? That’s agribusiness.

I don’t know where to draw the lines. But when chickens have huge open bedsores on their undersides, I wonder if that isn’t less animal husbandry than animal abuse.