This could lead to the odd case of poisoning. Ragwort - Cattle and horses are most susceptible, resulting in liver damage. The fresh plant is bitter, but dried is sweet. Death could follow. Bracken - Animals only eat bracken if hungry, and clinical signs don't develop for 2 to 8 weeks.
Cattle become anaemic, have runny noses, difficulty breathing and scour.
Oak - Both the leaves and the acorns contain toxins. These cause gastrointestinal upsets and consequent abdominal pain. Growing well in hedgerows, this plant contains the same poison as found in green potatoes. It causes scouring due to ulceration of the intestines, and death if eaten in sufficient quantities. This plant grows in ditches and rhynes.