does wild parsnip affect horses
The three most common toxic weeds to horses that may be contained in hay are: Hoary alyssum, wild parsnip and poison hemlock. 1  Hoary alyssum - Hoary alyssum is a perennial weed. 2  Wild parsnip - Wild parsnip is mainly found in ditches and fields and is a biennial and is poisonous to horses. 3  Poison hemlock - Poison hemlock is poisonous to horses.