What is Clover Allergy ?

Food allergies in horses are rare but not unheard of.  Usually, food allergies in horses involve wheat and barley, but clover can happen in some. There are many species of the clover plant so your horse may be allergic to one but not another.  Symptoms of food allergies may include pruritus, generalized or multifocal, hives, tail rubbing, and even alopecia.  

Coming to a proper diagnosis can be tricky as there is no serologic or intradermal test reliable for food allergies.  If you are able to identify the source of the allergy and remove it from your horse’s diet, he should no longer suffer the allergy symptoms.  If you cannot determine the cause, then treating your horse in response to his symptoms is also good.  Prognosis of recovery from a food allergy in horses is good.

If your horse develops any type of abnormal skin condition, you should contact your veterinarian for evaluation.  It could be indicative of a food allergy that needs to be addressed before it continues.

Symptoms of Clover Allergy in Horses

Symptoms of a clover allergy in your horse may include:

  • Generalized pruritus
  • Multifocal pruritus
  • Pruritic urticaria
  • Non-pruritic urticaria
  • Tail rubbing
  • Scratching against posts or other objects 
  • Hives 
  • Alopecia 

Symptoms typically affect the: 

  • Neck
  • Face
  • Trunk
  • Rump 


There are many species of clover your horse may be allergic to.  Depending where you live, what type of soil you have on your property, and what season it is at the time of ingestion, the species can vary.  There are not many documented cases of a clover allergy in horses, but that does not mean it cannot occur.  Many times pigs are the ones with a clover food allergy, not horses.



Causes of Clover Allergy in Horses

Just like with any type of allergy in general, it is the immune system thinking something harmless is actually dangerous.  In this case, your horse’s body thinks the clover he is ingesting is dangerous to him so his body is reacting in the only way it knows how to.  It can happen at any age, but it most frequently occurs in younger horses.  It is also thought that a food hypersensitivity can be a result of a break in the intestinal barrier function which causes an abnormal immune response to the antigen in the clover.



Diagnosis of Clover Allergy in Horses

Your veterinarian will begin by performing a full physical exam on your horse.  She will make note of all his symptoms and where they are primarily affecting him on his body.  She will also want to collect a verbal history from you including what your horse has ingested and has had contact with recently.  

As a safety precaution, your veterinarian may want to take a skin scraping sample from your horse for skin cytology.  These tests can rule out skin issues that may be affecting your horse such as parasitic infections, fungal skin infections, or other likely skin ailments.  It is common to find a secondary bacterial infection associated with a food allergy.  Your horse may be so itchy that he scratches himself constantly until he is raw, allowing bacteria to gain entrance via the broken skin.  

Unfortunately, there are no serum, blood, or intradermal tests reliable for diagnosing food allergies.  The main way to do it is trial and error dietary study.  Unfortunately, there is very little information on this in horses as their owners do not like to a novel protein.  On the positive side of this, food allergies in horses are reported as rare.



Treatment of Clover Allergy in Horses

The skin will need to be treated depending on the lesions and symptoms your horse has developed.  If there is a secondary infection, your horse will need antibiotics.  Your veterinarian may also recommend a topical medication in the form of a liquid, ointment, or spray for you to apply directly to the lesions themselves.  Your veterinarian may need to prescribe additional medications or therapies depending on the severity of your horse’s condition.

Finding the source of your horse’s allergy is ideal.  By determining what is causing your horse’s symptoms, you can then remove it from his diet and prevent his symptoms from remaining.  If you are not feeding him clover, then he may be finding it on your pasture.  You would then need to remove it from your field in order to stop him from ingesting it.



Recovery of Clover Allergy in Horses

If you are unable to determine the source of the allergy, you may have to provide your horse lifelong supportive therapies in response to his allergy symptoms.  This may include oral medications, topical ointments or sprays to control his symptoms. If you are able to find the source and remove it from his diet, he should no longer have clinical symptoms of food allergies.  Most horses do not have allergies to food and when they do their prognosis of recovery is good.



Clover Allergy Questions and Advice from Veterinary Professionals

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© 2022 Wag Labs, Inc. All rights reserved.