Downed animals, according to the animal protection group, are those too sick or ill to walk on their own.
HSUS Senior Vice President Wayne Pacelle asked Veneman to exercise her authority to prohibit the practice of processing of sick animals for human consumption.
"To allow the continued processing of downed and diseased animals for human consumption is reckless and irresponsible," Pacelle said.
The Agriculture Department reports that there are perhaps 130,000-190,000 animals that go down ever year and cannot stand again and that are presented at slaughterhouses, the HSUS said. Nearly three-quarters of those animals are processed for human food, often on the basis of only a visual inspection at slaughterhouses.