Coccidia are tiny internal parasites (Eimeria spp) that live in the cells of the animal’s intestines. The tiny oocysts containing the infective stages are passed in the feces and are picked up by other animals through contaminated feed and water. The number of parasites that invade the intestinal tract determine the severity of disease that results in the condition called coccidiosis.

Coccidia are considered internal parasites but are resistant and non-responsive to dewormers used for internal parasites. Practically all animals tolerate a low level of coccidia with no adverse effects. A high level of coccidia, especially in young animals, damages the intestinal lining resulting in improper or reduced absorption of nutrients and weight loss. This damage can also result in bloody and dark diarrhea, causing dehydration and death. In some cases, very little diarrhea, if any, has been observed. Stress induced from changes in weather or sudden changes in feeding, such as from pasture to dry lot, will often result in a severe coccidia

Corid is the number one best selling treatment for control of cocidiosis. Structurally, CORID mimics thiamin (Vitamin B1) which is required by coccidia for normal growth and reproduction. When coccidia ingest CORID, they experience thiamin deficiency and starve from malnutrition. CORID has been experimentally administered at many times the recommended dosage and duration with no signs of toxicity. CORID stops coccidia at a critical stage in the host animal's small intestine to prevent more damaging coccidiosis in the large intestine. By acting on the young asexual stages of the coccidia life cycle, CORID allows exposure to first-generation schizonts, so the host animal can develop natural immunity to coccidia. This makes CORID effective as a preventive therapy. ·  Administer CORID at the first clinical sign of coccidiosis, such as diarrhea and dehydration. ·  Drinking water or drench administration ensures CORID will reach the intestine, even in animals with reduced feed intake and low gastrointestinal motility. CORID should be used on a group, pen or herd basis. When one or more animals show clinical signs of coccidiosis, it's likely the rest of the group has been exposed to coccidia and all animals in the group, pen or herd should receive CORID.