Poinsettia plants (Euphorbia pulcherrima) produce a milky sap containing diterpenes and other irritants that make them toxic to cats. While not usually fatal, eating leaves, stems, or flowers can cause immediate symptoms like excessive drooling, vomiting, diarrhea, and skin or eye irritation if the sap contacts those areas. Severity depends on the amount ingested and the cat's size, but even brief nibbling poses risks. Prevention is key: place plants high or in cat-free zones during holidays. If ingestion occurs, induce vomiting only under veterinary guidance and seek prompt professional care to monitor for dehydration or complications. Myths about poinsettias being harmless are outdated; modern veterinary consensus confirms their toxicity.