The indictment last week of Atlanta Falcons quarterback Michael Vick on charges of running a dogfighting operation at a house he owned in Virginia shines a light on a disturbing phenomenon that law-enforcement officials say is flourishing across the country. Though dogfighting is a felony in all but two states (Idaho and Wyoming), at least 40,000 Americans are actively involved in the industry, not including spectators, according to Wayne Pacelle of the Humane Society of the United States. Mark Kumpf of the National Illegal Animal Fighting Task Force describes it as a multibillion-dollar industry. And anyone who believes, like Fat Dog, that the fights are just sport can read in the federal indictment about the fate that awaits some animals who quit or lose a match. When, according to the indictment, a female pit bull backed by Vick’s Bad Newz Kennels lost a fight in March 2003—and a purse worth $26,000—one of Vick’s associates allegedly “executed the losing dog by wetting the dog down with water and electrocuting the animal.” Vick’s attorney, Lawrence Woodward, told a Norfolk paper last week: “My client’s going to defend himself in court.”

To understand what dogfighting is really like, NEWSWEEK spoke to insiders and law-enforcement officials. Most described highly organized competitions marked by systematic cruelty.

Professional fights, like the ones Fat Dog attended, have very strict rules. Leading up to the battle, the dogs spend about six weeks in “the keep,” or in training. Owners often use expensive treadmills to get the dogs in shape, some even suspending a live cat in front of the dog to keep it running, according to police who have investigated dogfighting.

After the bets are made, the fight takes place in a walled ring with a dirt or carpet floor. The handlers wait to hear “Release!” and the battle is on until one dog fails to cross the “scratch” line or is injured too severely to continue. If the dogs lock up, their jaws are pried open with a “break stick.” Sometimes a dog will “fang” itself, or bite through its own upper lip.

Because both males and females are trained to fight, breeding can be tricky. Some dog owners use what is called a “rape box” to secure the female, which essentially means tying her to a barrel until the male has mated.

Fat Dog believes the negative publicity has an impact. “I don’t like the bad name it gives pit bulls—if you’re an owner you might as well live with Satan or be a child molester,” he says. But he admits the sport thrives on the spectators’ desire to see aggressive fighting. Owners, he says, most admire the dogs that won’t quit, even when they’re beaten and bloody.