Rick Dutrow had no idea how powerful a bomb he was detonating in May 2008, when he casually mentioned that Big Brown -- the Kentucky Derby winner who seemed destined for the Triple Crown -- was on steroids. Dutrow said he gave all his horses a shot of Winstrol every month, the same drug that has gotten many a human athlete banned from competition.

Although steroids were legal for racehorses at the time, Dutrow's admission, as well as his cavalier attitude, shocked the public. It merely confirmed what Jim Squires already knew: that a mix of scoundrels, con men and elite power brokers were ruining his beloved sport. The former newspaper editor turned horse breeder lays bare the industry's problems in "Headless Horsemen: A Tale of Chemical Colts, Subprime Sales Agents and the Last Kentucky Derby on Steroids," an insider's stunning account of the corrupt practices that threaten both the horses and the game.

Squires is among the few persistent voices for reform in thoroughbred breeding and racing. His book overflows with love for the horses he raises at Two Bucks, his small Kentucky farm, and with anger at the people whose greed is despoiling the sport. Squires' revelations about drug use are particularly damning, as are his accounts of how buyers at the nation's most exclusive auctions are cheated and misled.

"Headless Horsemen" explains how steroids came to be widely used, both to pump up young horses headed for auction and to enhance the performance of those on the track, and the inevitable ill effects. Squires tells shocking tales of the veterinarians who created racing's drug culture, offering speculation that one -- Dr. Alex Harthill -- may have pharmaceutically influenced the outcomes of dozens of Kentucky Derbies.

In the sale ring, he exposes the phony bidding, kickbacks and behind-the-scenes manipulations that pick the pockets of unsuspecting buyers and sellers -- including wine magnate Jess Jackson, whose fight to reform sales practices after his own fleecing is recounted in absorbing detail. Squires also explains how horses bred solely to fetch high prices at auction are weakening the breed, and how the sport's highly exclusive power structure discourages real change.

Squires' folksy style makes for an engrossing read. And his credibility, as well as his passion, lends power to his argument. He made his bones in the sport as the breeder of 2001 Kentucky Derby winner Monarchos, and he continues to breed and race horses despite his disgust at the state of the game.

"Racing will survive," Squires writes, "because horses are an addiction with no cure." For those who love it as much as he does, his fearless book stands as a rallying cry to save a sport insistent on poisoning itself.

Rachel Blount covers horse racing for the Star Tribune.