Coccidia are a group of microscopic parasites belonging to the class Apicomplexa. They primarily infect the intestinal tract of various animals, including mammals, birds, and reptiles. Coccidia reproduce within host cells, leading to cell damage and inflammation, which can cause gastrointestinal issues. Infections caused by coccidia, known as coccidiosis, can result in symptoms such as diarrhea, weight loss, and dehydration. Young or immunocompromised animals are particularly vulnerable. Treatment often involves medications that target the parasites, and prevention typically includes good hygiene and management practices in animal care settings.