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Coccidiosis in sheep

Coccidiosis stunts lambs and causes scours around weaning. Learn the signs, toltrazuril and diclazuril dosing, prevention, and when to involve a vet.

Ovine coccidiosis is caused by pathogenic Eimeria species (notably E. ovinoidalis and E. crandallis). It is host-specific to sheep.

Who is at risk

Lambs 4–8 weeks old, especially at weaning and in intensively stocked or wet conditions, carry the highest risk.

Symptoms of coccidiosis in sheep

  • Scours (diarrhea). Dark, sometimes blood-tinged diarrhea; dags around the tail.
  • Poor growth & ill-thrift. Lambs fall behind and look pot-bellied with rough wool.
  • Straining & dehydration. Persistent straining and weakness in heavier cases.
  • Subclinical loss. Many lambs lose growth without obvious scouring.

When to act

Blood in the stool, ongoing diarrhea, dehydration, or a young sheep going downhill all warrant prompt veterinary attention. Confirm the diagnosis with a fecal test rather than guessing.

Treatment

Effective options for sheep include:

  • Toltrazuril. In veterinary references, toltrazuril is commonly given to lambs as a single oral dose (around 20 mg/kg).
  • Diclazuril. A single-dose option, sometimes repeated in high-challenge situations.
  • Amprolium. A multi-day course; give thiamine afterward.

Pair any treatment with supportive care — fluids, nutrition, and a clean, dry environment. The dosage reference shows typical published figures; a veterinarian must confirm what's right for your animal.

Talk to a vet about sheep

Coccidiosis should be confirmed with a fecal test, and several anti-coccidial drugs require a veterinarian's prescription. Vetr connects you with licensed veterinarians who can diagnose, advise, and prescribe when appropriate.

Talk to a licensed vet

Prevention

  • Avoid building up contamination on the same lambing and creep areas year after year.
  • Keep feed and water troughs clean and off the ground.
  • Reduce stocking density and stress at weaning.
  • Time preventive treatments to the period of highest challenge, on veterinary advice.

Is it a risk to me or other animals?

Sheep coccidia are host-specific and pose no risk to humans or other species.

Frequently asked questions

When should I treat lambs for coccidiosis?
Treatment is usually aimed at the window when challenge peaks — often around weaning. A vet can help you time a single-dose toltrazuril or diclazuril treatment, or a preventive program, to your flock's pattern.
Why are my lambs poor despite worming?
Coccidiosis is a common hidden cause of ill-thrift that worming won't fix. A fecal test that speciates the coccidia helps distinguish harmful Eimeria from harmless ones.
Is lamb coccidiosis the same as in goats or calves?
The disease is similar, but the parasite species are host-specific — lambs, kids, and calves each have their own Eimeria, so they don't infect one another.
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Questions about sheep coccidiosis?

A licensed veterinarian can confirm the diagnosis and advise on the right approach for your sheep. Vetr offers veterinary consultations.

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Educational information only — not veterinary advice, and not an offer to sell any product. Coccidiosis.com provides general educational information about animal health and does not diagnose, treat, or prescribe. Some medications discussed (including toltrazuril and diclazuril) are not approved by the U.S. FDA for use in animals, and others are approved only for specific species; any use must be determined and supervised by a licensed veterinarian, who can also advise on correct dosing and withdrawal times. Always consult your veterinarian before using any medication.