Suspected tremetol poisoning in horses.

The research article reports the poisoning of horses by a plant based toxin called tremetol. On an overgrazed pasture, out of 10 horses, four ended up dying with symptoms like muscle tremors, sweating, reluctance to walk and myoglobinuria. Through clinical signs and other factors, it was concluded that the horses may have died from ingesting the Eupatorium rugosum plant, also known as white snakeroot.

Introduction

• The research investigates the cause of the death of horses in an overgrazed pasture.
• Of the ten horses on the pasture, four showed severe symptoms and died within a week.

Observations and Initial Findings

• Populating the symptoms of the horses, they included muscle tremors, ataxia which is a lack of muscle control, reluctance to move, and heavy sweating. The horses also exhibited myoglobinuria which is a condition characterized by the presence of myoglobin in urine, often due to muscle degradation.
• There were high activities of serum creatine kinase, aspartate transaminase, and alkaline phosphatase. These enzymes indicate muscle damage and general clinical chemistry changes that often manifest in illness.
• Upon histopathological examination, the findings were nonspecific. This could suggest that the cause of the symptoms and subsequent deaths was not immediately identifiable from the tissue samples alone.

Investigation and Conclusion

• The pasture condition, along with the identification of heavy-use white snakeroot plants, indicated the possibility of dietary causes to the health issues. Snakeroot plants were noted from which a toxin called tremetone was found. These plants show signs of being heavily browsed, suggesting the likelihood of ingestion by the horses.
• Putting together the clinical signs, the clinicopathological and histopathological findings, and the evidence of heavy consumption of white snakeroot plants, the research reached a conclusion that the horses died due to ingestion of Eupatorium rugosum, or white snakeroot which contains the toxin tremetol.