Products & Articles

Immune Support and the Horse

Does your horse have a healthy and strong immune system?  Is your horse in need of immune support? How do you know?  The most common problems we associate with a poor immune health are recurrent infections and even allergies, but what about other conditions?  Even in the case of infections, we most often attribute a poor immune response to more severe infections that may even result in hospitalization, but are there other clues or more subtle situations that may indicate that we have a problem?  The immune system is complex and involved in more bodily processes than one might just realize.

Immune Support in the Horse
Immune Support in the Horse

The immune response is a complex system that starts at birth and develops over time.  The first few hours of life for a newborn foal can determine the course of many months to come due to proper ingestion of colostrum, which helps to protect against foreign invaders.  Those foals that fail to ingest adequate amounts of high quality colostrum are usually at risk of many types of infections, which can impact overall health and future performance. As the foal ages, his or her natural immune system begins to develop and take over the protection from that point forward.,through the help of vaccinations and natural exposure.  A more detailed discussion regarding the immune response can be found here:

When we look at the adult horse, we often assume that their immune response is intact and healthy.  As horse owners, we adhere strictly to the guidelines from our veterinarian, performing vaccinations as needed, so we should be protected…right?  Maybe we even have yearly bloodwork done and everything looks fine. The immune response should be strong, correct?

Clues to Poor Immune Health in the Horse

The reality is that there are more subtle clues that maybe your horse’s immune response may need a boost or increased support.  

  • Ongoing or seasonal skin problems (yeast, fungal or bacterial)
  • Coughing, which may be seasonal and productive or non-productive
  • Recurrent respiratory infections or allergies
  • Presence of aural plaques (white patches inside of the ears)
  • Recurrent hoof abscesses, thrush or white line disease
  • Increased intestinal parasite (worm) counts
  • Diagnosis of EPM or Lyme disease
  • Poor recovery or healing from tendon or muscle injury
  • Poor healing of wound
  • Ongoing swelling or stocking up in the legs (lymphangitis)

That is my short list for clinical clues, but there are also specific groups of horses that would benefit from boosting the immune response, which include:

  • Horses under a heavy training or competition schedule
  • Horses with high levels of anxiety and stomach ulcers
  • Horses that require repeat courses of antibiotics, antiprotozoal medications and dewormers
  • Horses housed in large populations in close quarters
  • Horses housed in operations where there is a high influx of new horses
  • Horses that fail to respond properly to vaccines or have reactions

These are all observational conclusions made over the course of my career, and looking at these two lists, one could conclude that all horses could use some immune enhancement, but why?

As mentioned, the immune system gets its roots when the horse is first a foal.  As time goes by, the immune response begins to mature and develop due to exposure to antigens in the environment and vaccines.  But despite this, not every horse develops the same and some are stronger than others.

Factors Contributing to Poor Immune Health in the Horse

We can’t forget that the immune system is impacted by many other factors, which dictate how strong it may be, including:

  1. Diet
  2. Environmental Factors
  3. Stress
  4. Genetics
  5. Inflammation

We have to take all of these factors into consideration and realize that each plays a major role in the function of the immune response.  Those horses that are undergoing frequent training, competition and transportation are often highly stressed, which negatively impacts the immune system.  When we compound this with a poor diet, high exposure rate to other horses and the presence of ongoing injuries, the situation is often compounded.  It is not surprising that we tend to encounter more types of infections in these horses ranging from respiratory disease to EPM and even Lyme.

But what about the average pleasure horse, that seems to live a stress free lifestyle?  For sure, they are in a different group, but many of these horses often have immune problems ranging from repeat skin infections to allergies and even recurrent hoof abscesses.  Often these are attributed to deficient diets and even ongoing stress associated with herd incompatabilities or environmental influences.

No matter the problem we are faced with regarding our horse, we should always ask two questions:

  1. What is the current problem and cause?
  2. What, if anything, opened the door for this problem to happen? (why my horse?)

I raise these two points because all too often we are treating the same problem over and over again, instead of looking for ways to prevent or control it more readily. I think often times, we are not looking for the root cause that opened that door for the problem to develop. In many situations, including repeat cases of hoof abscesses and injuries that fail to heal, the immune system is actually depressed and by supporting it, our results can be enhanced several fold.

Methods to Provide Immune Support and Boost Health in the Horse

Diet: A high quality diet is one of the most vital aspects of supporting the immune response.  The actual definition of a high quality diet is debatable and a topic for another discussion, but in a basic sense, ideally we feed high quality forage, have access to a good pasture and feed as little processed feeds as possible.  Many foods have the ability to boost the immune response due to provision of micro and macronutrients, but also antioxidant support. On the same coin, many processed foods and diets can actually negatively impact the immune response.

Reduce Stress: Allow your horse to just be a horse as often as possible, which includes adequate turnout and free time.  If there is a problem within the herd, look for an alternative in terms of turnout or stabling. When stress cpannot be avoided, high quality feeding programs and proper supplementation can help to reduce the negative impacts.

Vaccines/ Deworming:  Perform vaccinations as recommended by your veterinarian and deworm as indicated to help reduce burdens.

Control Inflammation:  Inflammation is an ongoing process but heightened in many situations as a result of training, stress, injury or concurrent health problems.  Managing the inflammatory response can help to keep the immune system in check and functioning at a proper level.  Useful herbs include Boswellia, Curcumin, Ashwaghanda, and Flax along with antioxidants have been proven beneficial.

Immune Supplementation: Use of antioxidants and various herbs, including medicinal mushrooms (Shiitake, Maitake and Cordyceps) can have a profound effect due to their ability to awaken the immune system, improve its overall reactivity and even support normal cellular function.

In my clinical experience, immune dysfunction is a common problem and the question comes as to how best to manage it, which can vary from one horse to the next.  We need to determine the cause of the immune dysfunction, modify it and then support the body for optimal health.

Diet is a key point that we approach with all of our patients, trying to establish balance and support cellular health.  We do use many supplements, often in the form of herbs, which can provide substantial results.  One or my personal favorite group of herbs for direct immune support are medicinal mushrooms, of which there are many.  These mushrooms not only help to boost the immune response and even manage the inflammatory response, but also provide the body with needed antioxidant support and nutrients for optimal cellular health.  The formula that we tend to use often is the Cur-OST® EQ Immune & Repair, which utilizes a micronized and concentrated blend of several medicinal mushrooms in combination with vital amino acids needed to support normal cellular function and tissue repair.

All horses are individuals and with this, their needs vary tremendously.  Those needs are not always obvious, but often times, we need to step back and evaluate the situation in more detail. Given the importance of the immune response not only for infection prevention, but also in the healing process, proper immune support becomes a necessity for long term health and even soundness, not only for the performance equine athlete, but also for the pleasure horse.


All my best,

Tom Schell, D.V.M.

Nouvelle Research, Inc.



Leave a Comment

Your email address will not be published. Required fields are marked *