Coccidia is one of the more common ones. Coccidia is a protozoan — a one-celled organism — not a worm, as many people think. Coccidia are microscopic, or not visible to the naked eye ...

But if that diarrhea is watery and doesn’t respond to the usual treatments, it could be a sign of a coccidia infection, also known as coccidiosis. While coccidia in dogs can become serious ...