Walnuts pose multiple risks to dogs. Black walnuts and their husks contain juglone, a natural toxin that can lead to gastrointestinal distress, lethargy, and in severe cases, seizures or liver damage. English walnuts, while lacking juglone, are high in fat, which can trigger pancreatitis a painful condition involving vomiting, abdominal pain, and potentially life-threatening complications. Additionally, walnuts are prone to mold growth producing aflatoxins, highly toxic to the liver. Symptoms of ingestion include drooling, tremors, weakness, and jaundice. Veterinary treatment is often required. Safer treats include dog-specific options like carrots or apples (without seeds).