In 1998, two samples of Nutro Premium (together with various other brands) were subject to qualitative analyses for pentobarbital residue by the U.S. Food and Drug Administration Center for Veterinary Medicine (CVM) due to suspicion that the anesthetizing drug may have found its way into pet foods through euthanized animals, including cats and dogs. DNA test for all the samples failed to detect cat and dog DNA but Nutro's two samples tested positive for the drug, presumably from rendered cattle. The CVM stated that due to the low level of exposure, the risk of adverse effects is low.