Jill Hennessy

Luck, the HBO drama series about horse-racing, has temporarily suspended the use of horses during production after a third horse was injured and forced to be euthanized on set, according to The Hollywood Reporter.

The incident happened early Tuesday when the horse suffered an accident while returning to its stall.  The show, currently filming its second season, had to put down two horses that were injured during the filming of Season 1.

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"We will not be filming horses until [the American Humane Association] completes its inquiry. Production will continue with other scenes," HBO told The Hollywood Reporter. "Everyone associated with Luck cares deeply about the well-being of the horses who are so much a part of the heart and soul of the production."

People for the Ethical Treatment of Animals (PETA) has called for production to be shut down, and has slammed the network and the show's executive producers David Milch and Michael Mann for the previous incidents. In a statement on its site, PETA had "sent a complaint to Los Angeles law enforcement urging the agency to investigate the deaths of two horses during the filming of the first season."

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Upon hearing the news of the third horse's death, the animal rights organization said, "We think — and we hope law enforcement agrees — that the way in which the horses were treated by the production company, the trainer, and the veterinarian warrants a swift and thorough investigation before yet another horse dies."