Overview. Lupine plants may be beautiful to look at, but can be toxic to animals, even in small doses. Larger doses may result in a variety of symptoms or death, even if those larger doses are the result of accumulations over time.ypes. While most members of the lupine family are poisonous, that is not true of all of them. According to the United States Department of Agriculture, is known that yellow lupine, silvery lupine, silky lupine, tailcup lupine, velvet lupine and lunara lupine are definitely poisonous.