Cats can eat butter in small amounts without being toxic or immediately harmful, but it is not recommended to feed them butter regularly. Butter is safe in small quantities, but it is high in fat and contains lactose, which many cats are intolerant to. Excessive butter consumption can cause digestive upset such as vomiting, diarrhea, and more serious conditions like pancreatitis, as well as contribute to obesity and other health issues. Butter does not provide nutritional benefits suited to cats, who require a high- protein diet from meat. Therefore, butter should only be an occasional accidental or tiny treat and not a part of a cat's regular diet.