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Coccidiosis in horses

True intestinal coccidiosis is uncommon in horses. Learn what it is, how it differs from EPM, treatment with amprolium, and when to consult your vet.

True intestinal coccidiosis is uncommon in horses; when it occurs it involves Eimeria leuckarti. Note that EPM — a serious neurological disease — is caused by a different coccidian parasite (Sarcocystis neurona) and is not the same as intestinal coccidiosis.

Who is at risk

Foals and young horses are the most likely to show intestinal coccidiosis, though many infections cause no clinical signs at all.

Symptoms of coccidiosis in horses

  • Often no signs. Many horses shed the parasite without becoming ill.
  • Diarrhea in foals. When disease does occur, loose manure and poor thrift are the usual signs.
  • Weight loss / poor growth. Affected foals may fall behind.
  • Not to be confused with EPM. Stumbling or muscle wasting points to EPM, a separate disease — call your vet.

When to act

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

Treatment

Effective options for horses include:

  • Amprolium. Used off-label in horses for intestinal coccidiosis; supplement thiamine and involve your vet.
  • Supportive care. Fluids and nutrition support recovery in affected foals.

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 horses

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

  • Keep foaling and weanling areas clean and dry.
  • Provide clean feed and water off the ground.
  • Don't self-treat suspected neurological disease — EPM needs specific veterinary diagnosis and drugs.
  • Confirm any diagnosis with a fecal test and your vet before treating.

Is it a risk to me or other animals?

Equine coccidia are host-specific and are not a human health risk.

Frequently asked questions

Is coccidiosis common in horses?
No — true intestinal coccidiosis is relatively rare in horses, and many infections cause no illness. Persistent diarrhea or poor growth in a foal has many possible causes and should be worked up by a vet.
Is EPM the same as coccidiosis?
No. EPM (equine protozoal myeloencephalitis) is caused by a related but different coccidian parasite and affects the nervous system. It requires specific veterinary diagnosis and treatment — don't treat it as gut coccidiosis.
How is equine coccidiosis diagnosed?
Through fecal testing by a veterinarian. Because signs overlap with other conditions, professional diagnosis is important before any treatment.
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Questions about horse coccidiosis?

A licensed veterinarian can confirm the diagnosis and advise on the right approach for your horse. 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.