Coccidia are tiny, single-celled parasites that primarily infect the intestines of animals, including pets like dogs and cats. They belong to a group called protozoa and can cause a disease known as coccidiosis. Infected animals may experience symptoms such as diarrhea, vomiting, and weight loss, especially if they are young or have weakened immune systems. These parasites are often spread through contaminated food, water, or feces. While coccidia can be harmful, most healthy animals can recover with proper treatment. It's important for pet owners to maintain good hygiene and consult a veterinarian if they suspect their pet has coccidiosis.