Yes. In particular, the roots and seeds of the plant are toxic due to the cardiogenic compounds they contain. In small amounts, it is possible that the only results of consuming these toxins could be heart palpitations and gastrointestinal symptoms. But columbine poisoning can be lethal. So, even though there is a history of medicinal use of the root of columbine among members of indigenous tribes, you should not eat it! You might be wondering if columbines are poisonous for cats, dogs and horses, or just to you. The Deerfield Veterinary Clinic clearly lists columbines among “plants poisonous to your pets.” So, the answer is, “Yes.” Columbines are toxic to humans and animals. So, definitely keep your pets away from your columbine plants.