Animal Welfare Institute (AWI) federal policy advisor Liz Ross was referring to the estimated 100,000 horses purchased at auction by killer-buyers for export to Canada and Mexico.
The trade has grown massively since legal challenges forced the closure of three slaughter plants in the US.
Ross told the the House Judiciary Committee Subcommittee on Crime, Terrorism and Homeland Security: "Every five minutes an American horse is slaughtered to fill the demand of high-end European and Asian diners."
She was speaking in support of a bill to end the transport and slaughter of America's horses.
The Prevention of Equine Cruelty Act of 2008, HR 6598, carries criminal penalties for the purchase, sale, delivery or export of horsemeat intended for human consumption including fines and prison time.
It was Introduced a week ago by House Judiciary Committee chairman John Conyers, jun. (D-MI) and Representative Dan Burton (R-IN).
The bill would provide US government officials and law enforcement officials with the tools necessary to ensure that American horses are protected from the horsemeat trade.
The bill has already garnered bipartisan support.
"This issue," Ross told the committee, "has been vetted in Congress on multiple occasions and every time any measure to prohibit or restrict horse slaughter comes up for a vote the tally is overwhelming in favour of ending this form of animal cruelty."
Ross said horse slaughter is a form of animal cruelty and ought to be recognised and treated as such.
"I am proud to be a co-sponsor of HR 6598," said Burton. "We must treat these magnificent animals with the respect and dignity they deserve."
Chris Heyde, deputy director of government and legal affairs for AWI, thanked those committed to the passing of the bill.
"Now that HR 6598 has moved from subcommittee, we hope the Speaker and the Senate will provide similarly swift consideration for a policy that is supported by the vast majority of Americans."
Others testifying before the subcommittee in favour of the bill were" Dr John Boyd, President of the National Black Farmers Association; Wayne Pacelle of the Humane Society of the United States and Dr Nick Dodman of Veterinarians for Equine Welfare.
A 2006 national poll conducted by Public Opinion Strategies found that almost 70% of Americans support a federal ban on horse slaughter.