Newborn kittens enter the world with almost no defenses of their own. For their first few weeks, they rely on antibodies passed from their mother’s milk to help protect them from disease. But once they’re weaned — or if they’re orphaned from birth — that natural protection fades quickly, leaving them vulnerable to viruses that can spread fast and turn deadly in a matter of days.

If you’re caring for a kitten and suddenly notice loose stool, you’re not alone. Diarrhea is one of the most common issues we see in young kittens. The good news is that many cases are manageable. The key is understanding what’s causing it and knowing when it’s time to seek help. Let’s walk through the most common reasons kittens develop diarrhea.