Slaframine Toxicosis in Horses

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Key takeaways

Slaframine toxicosis occurs when horses ingest high levels of slaframine toxin. Slaframine is a fungal toxin produced by the Rhizoctonia leguminicola fungus, commonly found on the red clover plant, alfalfa, and legumes.

  • Slaframine toxicosis is not life threatening
  • The main symptom of slaframine toxicosis is excessive salivation
  • Other symptoms include excessive urination, excessive tear production, diarrhea, and mild abdominal pain
  • Diagnosis is based on physical examination and feed analysis
  • Symptoms of slaframine toxicosis generally resolve without treatment
  • Abundant water and clean feed are the standard treatment
  • Prognosis is generally excellent
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A closer look: Slaframine Toxicosis in Horses

Slaframine toxicosis is not an emergency. Once symptoms appear, prompt medical attention is recommended to rule out any other conditions causing excessive drooling, such as dental disease.

Once the infested feed is replaced, recovery is expected within 12 hours to four days.

Risk factors

Horses that pasture in fields with the red clover plant, alfalfa, and legumes or those fed with hay made from these are more at risk of developing slaframine toxicosis. Slaframine toxicosis is more prevalent in warm and humid areas.

Possible causes

Slaframine toxicosis is caused by the ingestion of the fungal toxin slaframine, produced by the Rhizoctonia leguminicola fungus. The fungus is commonly found in:

  • Red clover
  • Alfalfa
  • Other legumes

Main symptoms

The onset of symptoms generally occurs within 1 to 6 hours after ingestion. The main symptom of slaframine toxicosis is excessive salivation.

Testing and diagnosis

Diagnosis is based on history of exposure and physical examination.

Definitive diagnosis is obtained by a positive fungus identification in the feed.

Steps to Recovery

Treatment involves

  • Replacing the infected feed
  • Providing access to abundant clean water

Prognosis of slaframine toxicosis is generally excellent, with most horses recovering within the first 24-48 hours. It can take up to 4 days to recover completely.


Slaframine toxicosis is not contagious, however all horses eating the same feed may be affected similarly.

Providing clean, uncontaminated feed is the best way of preventing slaframine toxicosis. Ensuring adequate access to clean and abundant water is the best way to ensure fluid replenishment.

Is Slaframine Toxicosis in Horses common?

Slaframine toxicosis is uncommon. Usually, multiple horses in the same area are affected.

Typical Treatment

  • Removal of infected feed


Karyn Bischoff BS DVM MS DipABVT; Birgit Puschner DipABVT PhD DVM - Writing for Vetlexicon
No Author - Writing for The Horse
Michelle S. Mostrom , DVM, MS, PhD, DABVT, DABT - Writing for MSD Veterinary Manual

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