Dogs are second only to coyotes as sheep killers. In 2004, coyotes killed more than 135,000 sheep nationwide, while dogs slaughtered some 30,000. The dogs "literally tear the hides off the animals, opening up their gut cavities and tearing up their faces," says Peter Orwick, executive director of the Denver-based American Sheep Industry Association.

"Dogs have been our worst nemesis over the last 20 years," agrees Don Watson, owner of Napa Valley Lamb Company in California and Rocky Mountain Wooly Weeders in Loveland, Colo. His sheep dogs -- Great Pyrenees that can weigh up to 120 pounds -- are effective at keeping wild predators like coyotes and mountain lions away. But dogs are relentless, wearing the Great Pyrenees down, chasing the sheep until they can no longer run and then killing them.

"The worst night I ever had, I lost 17 sheep," Watson says, when dogs from a neighboring ranch miles away got into his Napa corral.

Each year, Wildlife Services receives hundreds of requests to trap, poison and shoot feral dogs. Still, the agency devotes most of its resources to killing wild predators. In 2006, the agency killed more than 87,000 coyotes but only 512 dogs. Hundreds more were taken to animal shelters.

In California's San Gabriel and San Bernardino mountains, officials have removed 350 feral and free-roaming dogs over the past 15 years. The dogs are difficult to catch, and trapping has been sporadic at best. Recent U.S. Forest Service budget cuts will further hamper efforts to address the problem.

That leaves local officials like Villepique groping for a solution.

As the sun breaks through the morning mist off Mount Baldy Road, Villepique recalls how the dog he saw feeding on the bighorn carcass fled to a nearby area pocked with cabins. Unable to locate the dog's owner, he plans to work with animal control to help enforce laws that require folks to keep dogs on leashes or behind fences. He is trying to educate local residents and wants stiffer penalties for repeat violators.

And if that doesn't work, there's always the bear spray.

The author freelances from Claremont, California.