Lawmakers in California and Illinois have banned the slaughter of horses for human consumption, and more than a dozen states tightly regulate the sale of horse meat.
Federal lawmakers' lifting of the ban on funding for horse meat inspections came about in part because of the recession, which struck just as slaughtering stopped. A federal report issued in June found that local animal welfare organizations reported a spike
in investigations for horse neglect and abandonment since 2007.
In Colorado, for example, data showed that investigations for horse neglect and abuse increased more than 60 percent -- from 975 in 2005 to almost 1,600 in 2009.
The report from the U.S. Government Accountability Office also determined that about 138,000 horses were transported to Canada and Mexico for slaughter in 2010, nearly the same number that were killed in the U.S. before the ban took effect in 2007. The U.S. has an estimated 9 million horses.
Cheri White Owl, founder of the nonprofit Horse Feathers Equine Rescue in Guthrie, Okla., said she's seen more horse neglect during the recession. Her group is caring for 33 horses now and can't accept more. "A lot of the situation is due to the economy," she said, "People deciding to pay their mortgage or keep their horse."
But White Owl worries that if slaughterhouses open, owners will dump their unwanted animals there instead of looking for alternatives, such as animal sanctuaries.
Animal rights groups also argue that slaughtering is a messy, cruel process, and some say it would be kinder for owners to have their horses put to sleep by a veterinarian.
"Euthanasia has always been an option," Pacelle said. But "if you acquire a horse, you should be a responsible owner and provide lifetime care."
The fight over horse slaughtering has pitted lawmakers of the same party against each other.
Sen. Max Baucus, D-Mont., said the poor economy has resulted in "sad cases" of horse abandonment and neglect and lifting the ban will give Americans a shot at regaining lost jobs and making sure sick horses aren't abandoned or mistreated.
But U.S. Rep. Jim Moran, D-Va., is lobbying colleagues to permanently ban horse slaughter because he believes the process is inhumane.
"I am committed to doing everything in my power to prevent the resumption of horse slaughter and will force Congress to debate this important policy in an open, democratic manner at every opportunity," he said in a statement.