Coccidiosis
Coccidiosis is a common disease in sheep caused by protozoan parasites of the genus Eimeria. These microscopic parasites live and reproduce inside the cells of the sheep's intestines. While many species of Eimeria can infect sheep, only two (Eimeria ovinoidalis and Eimeria crandallis) are known to cause significant disease.
Symptoms and diagnosis of coccidiosis in sheep 🩺
Symptoms
Coccidiosis is most commonly seen in lambs aged four to eight weeks. The primary symptoms include:
- Severe, bloody diarrhea that may contain mucus
- Straining and abdominal pain
- Weight loss and poor growth rates
- Dehydration and, in severe cases, death
Older lambs may show ongoing poor growth rates due to the gut's reduced ability to absorb nutrients.
Diagnosis
Diagnosis is based on clinical signs and confirmed through laboratory tests. Faecal samples can be analyzed to identify a significant count of pathogenic coccidia oocysts. In severe cases, post-mortem examination may be necessary to confirm the presence of coccidia in the gut.
How to treat coccidiosis in sheep 💊
Treatment should be administered to the entire flock rather than individual animals, as asymptomatic lambs can still spread the disease. The following medications are commonly used:
- Decoquinate: An in-feed medication that requires a prescription and is incorporated into commercial creep feeds.
- Diclazuril and Toltrazuril: Oral drenches used for treating outbreaks. These should be administered to all lambs over three weeks of age in affected groups.
Supportive care, including oral electrolyte solutions and nursing, is essential for lambs with severe diarrhea and dehydration. Ensure they are protected from adverse weather and predators.
How to prevent coccidiosis in sheep 🛡️
Biosecurity and Hygiene
Good biosecurity and hygiene practices are crucial in preventing coccidiosis. This includes:
- Thoroughly cleaning and disinfecting housing and pen materials before lambing and between groups
- Reducing stocking density and ensuring adequate ventilation and drainage
- Regularly moving lambs to clean grazing areas and avoiding fields that carried young lambs in the previous season
- Cleaning and disinfecting milk feeding equipment, water buckets, and feed troughs regularly
Targeted Preventative Treatment
Preventative treatments can be administered based on the farm's history and screening results. High-risk lambs should be targeted for treatment to prevent clinical disease. Discuss with your vet to develop a strategic plan tailored to your farm's needs.
Building Immunity
Allowing lambs to be exposed to low levels of coccidia early in life can help them build immunity. However, ensure they are not overwhelmed by high levels of oocysts, which can lead to severe disease.