Horse Chestnut Toxicity in Horses

Horse Chestnut Toxicity in Horses - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost
Horse Chestnut Toxicity in Horses - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost

What is Horse Chestnut Toxicity?

There are a variety of trees and plants and flowers which, when ingested, are toxic to your horse.  Horse chestnut (Ohio buckeye), whose scientific name is Aesculus Hippocastanum or glabra, is one of those trees which is toxic to your horse.  It is utilized as a shade and ornamental tree and can also be found infrequently in many wooded areas.  While they may be beneficial for our human needs, for example the esthetic value of ornamentation and shade, they can be unhealthy and even deadly for your horse.

Horse chestnut, also known as Ohio Buckeye, an ornamental tree that is common to urban and rural areas, is one which can be toxic to your horse when any part of it is ingested.

Symptoms of Horse Chestnut Toxicity in Horses

Some of the trees, plants and flowers which are toxic to your horse can cause digestive issues while others can cause central nervous system problems.  Horse chestnut toxicity affects both the central nervous system as well as gastrointestinal system.  These are some of the symptoms you might see in your horse who has ingested these Ohio buckeyes;

  • Ataxia - inability to control muscles during voluntary movements like walking 
  • Colic
  • Red mucous membranes
  • Hypersensitivity
  • Muscle tremors
  • Weakness
  • Convulsions
  • Coma


There are no specific types of horse chestnut toxicities in horses. The types of symptoms which are generally exhibited by horses who have ingested the leaves, sprouts and nuts of the tree, with the young sprouts and seeds being particularly toxic to livestock including horses, are generally gastric and neurological in nature.  Not all horses suffer from poisoning after ingestion of the tree’s parts as some horses are more sensitive to the toxins than others.  The tree’s habitat consists of the rich, rocky woods of valleys, ravines, slopes, bases of bluffs and thickets and has been noted in Illinois and Missouri as well as other areas across the country.



Causes of Horse Chestnut Toxicity in Horses

While this tree may provide shade and be pleasing to the human eye, it has a nasty odor.  This is not a tree which normally attracts horses when they are grazing unless the other sources of food are scarce or the horse is bored.  Here are some things which you need to know about the cause of the toxicity:

  • The toxins usually attacks the gastrointestinal system of the horse first, causing salivation, abdominal pain and diarrhea
  • If the quantity of toxin ingested was great enough, the toxins will begin to affect the neurological system, causing signs like trembling, staggering and difficulty breathing
  • Coma generally precedes the death of the animal

The symptoms of horse chestnut toxicity is an emergency situation.  If you note any of these symptoms alone or in any combination or suspect that your horse has ingested any component of this tree, call your veterinary professional immediately.



Diagnosis of Horse Chestnut Toxicity in Horses

Diagnosis of this dangerous toxicity will be dependent upon a thorough history, physical examination and clinical signs noted by your veterinary professional.  He will likely also order blood work for further information and diagnostic assistance and support.  He will specifically be looking at blood protein levels. While there are a variety of trees, plants and flowers accessible to your horse when he grazes, many of them are toxic to his system.

Certain types of vegetation will leave specific markers in the blood and tissues of the equine.  It is these markers, along with your history, that your vet will be using to assess and determine which plant, tree or flower is causing the symptoms being exhibited by your horse.  Once the offending cause has been established, he will develop and initiate an appropriate treatment plan.



Treatment of Horse Chestnut Toxicity in Horses

Treatment of horse chestnut toxicity in horses generally consists of neutralizing the toxic agent which has been ingested by the afflicted horse and then various types of supportive care.  The treatment plan for your horse might include:

  • Activated charcoal - 1 to 2 g/kg given orally
  • Supportive care which includes IV fluids and analgesics and other medications to treat the symptoms being exhibited by the afflicted horse
  • Flushing the system with IV fluids will help to dilute the toxin in the horse’s system
  • Mineral oil can sometimes be given to act as a laxative to help eliminate the toxins more quickly

The quantity of the toxin consumed by the horse will determine the extent of the symptoms and progression of the toxicity.  Your vet will likely recommend any or all of the above treatment options as well as some not mentioned which will be determined by the symptoms and the condition of the horse.  He will need to treat the symptoms and any associated health condition found in his examination and assessment.



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Recovery of Horse Chestnut Toxicity in Horses

Depending on the quantity of horse chestnut consumed by your horse and the speed with which medical care and treatment was provided, the prognosis is usually good for a full recovery.  For the prevention of future episodes of toxicity for your herd, make yourself aware of the characteristics of the horse chestnut tree as well as other trees, plants and flowers which are noted to be toxic to horses.  Make every attempt to rid your property of those dangerous items to avoid poisoning of your horses in the future.  This may require removal of existing trees, sweeping the pasture to catch new growth of the trees and closely monitoring of hay and straw with removal of dried pieces of the leaves, sprouts or nuts.



Horse Chestnut Toxicity Questions and Advice from Veterinary Professionals

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