Contrary to popular belief, milk is generally harmful for cats. While often depicted enjoying a saucer of milk, most cats lack the enzyme needed to properly digest lactose, the sugar found in milk. This can lead to digestive upset, including diarrhea and vomiting. The common practice of giving milk to cats stems from a misconception and isn't beneficial for their health. Providing water is always the best option for hydration. Experts recommend avoiding milk altogether to prevent discomfort and potential long-term digestive issues in felines. Focusing on a species-appropriate diet is crucial for a cat’s wellbeing.