Supporters of these plants argue there is a market for horse meat abroad, but regulations in Mexico and Canada are lacking.
They say reopening plants here will make it humane, while allowing American meat industry to make a profit.
Animal rights activists are not buying it.
"The one thing about horses, is that they never forget anything," said Karen Pomroy.
She sees her 45 animals as loving companions.
"This one here, she was born here in a safe environment," she said, talking about a horse who came by to inspect our crew. "You can see how friendly she is."
But the owner of the Green Valley-based non-profit Equine Voices Rescue & Sanctuary knows her's is not the only view.
9OYS reporter Maggie Vespa said, "The idea of saving them from slaughter is a common theme around here."
Pomroy responded, "It is. Ninety-nine, 98 percent of the horses that are here would have otherwise gone to slaughter."
And it's a deed frequently done just outside the U.S., but that may soon change.
"There's no reason they shouldn't have a value after their usefulness is over," said Oklahoma State Rep. Skye McNeil (R).
Two years ago, Congress failed to renew a 2007 federal ban on horse slaughter plants.
So far, none have popped up, because the USDA never restored funding for required inspectors, but amid growing calls from the "meat processing" and other industries, lawmakers in New Mexico and Oklahoma are warming up to the idea.
"We need to be protecting those 160,000 horses by having regulated facilities in the U.S. that are USDA regulated," said Skye.
"Horses are different than cows," said Pomroy.
She argues, these plants were shut down for several reasons, incluing the method of slaughter.
"[It is a] spike that they shoot into the horse's skull, but because the horse is moving... They're very flighty animals, it could take nine times before they are rendered unconscious," she said.
Still, she knows the argument comes down to a disconnect in how society views these creatures and their purpose.
"Horses used to plow our fields. They used to carry our mail," said Pomroy. "They don't have those jobs anymore, and I think that if they were to be reclassified as companion animals they wouldn't be considered livestock and falling through the cracks."
There are differing takes as to why that Congress enacted the ban in the first place. Some called it a humane decision. Others called it a spending cut. USDA officials maintain that if plants in Oklahoma or New Mexico are approved, the horse meat would not be sold in the states.
It would be shipped abroad.
However, after seeing the problem pop up in Europe, critics argue this raises the risk of horse meat making its way into the beef supply here at home.