U.S. government scientists bought hundreds of dead dogs and cats from "Asian meat markets" and conducted experiments that included feeding their remains to healthy lab cats for needless research, according to a disturbing watchdog report being released Tuesday.

Other experiments at the U.S. Department of Agriculture's lab in Maryland included feeding dog remains to cats and injecting cat remains into mice, the report by the White Coat Waste Project found. The group is a non-profit that combats wasteful government spending on animal testing.

"It's crazy," Jim Keen, a former USDA scientist, told NBC News, which obtained a copy of the report. "Cannibal cats, cats eating dogs — I don't see the logic."

The experiments — some of which the agency said in scientific reports were aimed at studying different forms of a parasite that causes the food-borne illness toxoplasmosis — are believed to have been conducted between 2003 and 2015.

The USDA, which did not respond to requests for comment, has defended the cat testing in the past, calling it "life-saving research."

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