Although Congress lifted its ban in 2011, slaughtering horses for consumption didn't pick up again. In addition to certain state laws banning horse slaughtering -- in states where it often used to take place -- Hallman said money hadn't been put toward restarting the horse inspections.
"Unless you have a USDA inspector in a meat processing plant, you can't sell that meat legally," he said. "That doesn't mean someone is not doing it illegally."
Arnold said that despite the USDA checks in place, fraud can still happen.
"If you shut one door, they'll find a different way," Arnold said. "Even if it's not actually dangerous, it's horribly reprehensible to make someone take something into their body and mislead them as to what it is."