On this episode of Tox Talk, Dr. Brad White and Dr. Scott Fritz discuss a case where eight bred cows were moved into a barn ahead of a winter storm and were found dead the next morning. While initial concerns focused on the barn environment, testing revealed the cause was acute nitrate poisoning from newly introduced millet hay containing high nitrate levels. Nitrate toxicity can cause rapid death, often within hours, and may leave few obvious signs. This case is a reminder to consider what has changed when sudden losses occur, especially feed sources. Certain forages, including millet and other stress-grown crops, can accumulate nitrates, and toxicity persists after baling. Testing unfamiliar or newly purchased hay can help prevent devastating losses.