Coccidiosis is commonly referred to as “bloody scours” and costs the beef industry hundreds of millions of dollars every year. Coccidia are host-specific protozoan parasites; that is, they don’t cross species. Coccidia produce eggs called oocysts, which are shed in the feces of infected animals. Infected animals can either be showing symptoms or carrier animals showing no symptoms. The oocysts sporulate (mature) outside the body in moist, warm environments and become infective. The oocysts are then ingested by animals when they consume contaminated feed or water or by licking contaminated hair coats. Once the oocysts are ingested, the parasite can develop in the host animal, causing damage to the intestinal lining. If the intestinal lining is damaged enough, this can lead to diarrhea and bloody scours. Damage to the intestinal lining can also lead to the decreased ability of the animal to absorb fluids, which can exacerbate dehydration. These oocysts are resilient and can live for many years in moist environments.

Many animals can become exposed and infected with coccidia yet do not develop symptoms. These animals can develop immunity. The disease occurs when large numbers of oocysts are ingested. The disease can worsen in a stressed animal or one with a compromised immune system. The major stressful events that cattle experience, which could trigger clinical coccidiosis, would be weaning and shipping. Symptoms of coccidiosis are diarrhea with or without blood, depression, decreased appetite, dehydration, straining, sometimes neurological symptoms, and even death. Coccidiosis is usually a disease of the young unless older cattle are severely stressed. Calves as young as two weeks of age can be affected, but they are usually found dead. The life cycle for the maturation of the oocysts and for blood to develop in the feces is 21 days. Therefore, blood in the stools before 21 days of age is not due to coccidiosis. One of the main sources of exposure for young calves is drinking contaminated water from puddles. Coccidia can also present in a chronic form, which causes reduced growth rates. This chronic form is usually more costly to the cattle feeder than the acute form. The severity of the disease is dependent on the number of oocysts ingested. The more oocysts ingested, the more severe the disease.

Clinical signs, history of previous cases, fecal exam, or postmortem examination diagnose coccidiosis. By the time bloody scours occur, the disease is far advanced, and the affected animal is shedding millions of eggs daily.

Treatment for sick animals includes supportive therapy (fluids) and antibiotics to ward off secondary bacterial infections. Amprolium (Corid) at 5cc/100 lbs for five consecutive days and sulfa boluses are the treatment of choice for sick animals. If you see one clinical case, many more animals are in differing subclinical stages. Therefore, it is more cost-effective to prevent than to wait and treat.

Prevention focuses on decreasing exposure by cleaning the environment, including bunks and water tanks. Utilizing coccidiostats in feed or water works well. One essential recommendation is to offer calves a complete starter feed containing Decox or offer Corid in their water tanks. Be sure to consult your Sioux Nation veterinarian for complete recommendations. Major coccidian treatment prevention agents are Amprolium (Corid), Decoquinate (Decccox), Lasalocid (Bovatec), and Monensin (Rumensin).

Amprolium – 5mg/kg or 225mg/100 lbs. for 28 days (prevention)
10mg/kg or 450mg/100 lbs. for five days (treatment)
Decoquinate – 0.5mg/kg or 22.5mg/100 lbs. for 28 days (prevention)
Lasalocid – 1mg/kg or 45.5mg/100 lbs. for 28 days (prevention)
Monensin – 1.2mg/kg or 54.5mg/100 lbs. for 28 days (prevention)

Coccidiosis is a costly intestinal disease of young animals. It can cause subtle illness, severe illness, and possible death. Stress can induce clinical signs and cause animals to be more susceptible to secondary diseases. Control and prevention are accomplished by good husbandry measures to prevent ingestion of oocysts, along with the use of anticoccidial preventive therapies. The purpose of prevention therapies is not only to prevent disease in the animal but also to decrease the concentration of the parasites on the premises. Coccidiosis is a multifactorial disease that you don’t have to fight alone. We are here to help you. Please contact your Sioux Nation veterinarian for recommendations.