Veneman testified before the Senate Agriculture Committee, a day after the U.S. government said it is banning use of cattle blood in livestock feed to ward off a mad cow outbreak.
Countries across the globe halted beef imports from the United States after Veneman announced last month that a single cow had mad cow disease.
The United States has similarly banned imported beef from countries that discovered mad cow.
"Trade regulations, actions one country would take against another in the event of a single find, should be re-looked at," Veneman said.
"We are working with a number of other countries through the international organizations...to make sure this doesn't become a major trade problem" when only one cow is diagnosed with the disease, she said.
The government announced rules that will bar the use of cow brains and certain other animal parts in dietary supplements taken by humans.
Federal investigators also Monday they are winding down their search for potentially infected animals which grew up with the infected Holstein — America's first and only known case discovered last month in Washington state.
The announcements came a day before a Senate Agriculture Committee hearing on mad cow. Anne Veneman, and the Food and Drug Administration's deputy commissioner, Dr. Lester Crawford, testified.
On Monday, the Food and Drug Administration, trying to close loopholes in its bans on livestock feed ingredients, banned the use of blood in feed for cattle and other grazing animals, including sheep and goats.
The new steps "are intended to provide even greater security," said FDA Commissioner Mark McClellan.
Farmers have given feed containing blood to calves as a substitute for cow's milk, which is more valuable and sold for human consumption. But researchers and consumer advocates contended that blood might spread the fatal brain-wasting condition, formally known as bovine spongiform encephalopathy.
FDA also noted that Americans who spent substantial amounts of time in countries that had the rare human form of the condition, variant Creutzfeldt-Jakob disease, are not allowed to donate blood.
The main U.S. defense against mad cow disease is a 1997 ban on giving cattle feed made from the protein or bone meal of sheep or certain other mammals. Such feed is considered the most likely source of infection.