Milk sickness --also known as tremetol poisoning or in animals as trembles-- is characterize by trembling, vomiting, and severe intestinal pain that affects individuals who eat dairy products or meat from a cow that has fed on white snakeroot. Although highly rare today, milk sickness claimed thousands of lives in the early 1800s. A notable victim was Abraham Lincoln's mother, Nancy Hanks Lincoln. Nursing calves and lambs may have died from their mothers' milk contaminated with snakeroot even though the mother animals show no signs of poisoning. Cattle, horses, and sheep are the animals most often poisoned.