Impacts of Stress on Your Horse’s Health and Nutrition

Just like us, horses will experience different forms of stress in their day-to-day life. Usually, horses can tolerate short-term stress with little trouble. However, chronic stress can and does take a toll on their health and wellbeing. It is important to remember that despite our best-efforts, horses are going to experience stress in their life. However, our role as their caretakers is to ensure we help them by managing these stressors to lessen the impact on their lives.

What Types of Stress Do Horses Experience?

We can define the types of stress horses experience as being acute (short term) or chronic (long term). Generally, acute stressors are sudden or short-lasting events that the horse will overcome or eventually become accustomed to. Chronic stressors are longer-lasting events that persist for extended periods of time. For these, horses will need extra support to withstand the increased physiological demands placed upon them.

Some general situations that can cause your horse stress are:

  • Acute stressors
    • Sudden weather changes
    • Transport
    • Dietary changes or missed feeding times
    • Loud, unexpected noises
    • Abrupt change in routine
    • Foal weaning (affecting both foal and dam)
    • Competition/event
  • Chronic stressors
    • Exercise/training regimes
    • Lameness
    • Poor diet
    • Long periods of extreme weather
    • Parasites
    • Pregnancy
    • Extended confinement

There are many situations that can be considered stressful for a horse. There is also a wide variance in how an individual horse responds to a stressful situation. The important thing is to be able to distinguish between an acute and chronic stressor, so you know how to respond in your management.

How Does Stress Impact Horse Health and Nutrition?

When any horse is stressed, whether it be acute or chronic, their body responds by secreting a cascade of stress hormones. Cortisol is the most common stress hormone studied. There are diagnostic tests available that can measure cortisol levels in the blood, saliva or even in their feces. Cortisol levels can then be used to evaluate an individual horse’s stress levels.

One of the main purposes of stress hormones is to mobilize energy (glucose) in the blood when stress triggers a horse’s fight or flight instincts. Stress hormones cause both respiration and heart rates to increase, which helps increase glucose utilization, oxygen delivery, and other metabolic products to be processed as the horse gets ready to fight or flee (most common) from a stressful situation.

Acute stressors are usually not a cause for concern because they are so common in the daily life of a horse. However, short-term stress can lead to digestive upset, like colic. Because colic is a serious digestive disorder that is the leading cause of death of horses younger than 20 years of age, it would be worthwhile to review the following articles:

Chronic stress is more problematic for horse owners because some types of stress are not generally considered harmful for a horse. For example, exercise is a stressful event for a horse, but is generally viewed as beneficial. As long as the horse is in an appropriate training regime for their age and ability, and with appropriate recovery times, the stress experienced can be managed. However, chronic stressors, such as illness, lameness, or weather extremes, can be more difficult to manage.

A constant, daily excretion of stress hormones can have negative effects on a horse’s wellbeing. Chronic stress can lead to:

  • Weight loss
  • Gastric ulcers
  • Diarrhea
  • Hindgut upset
  • Reduced growth rates
  • Poor reproductive performance
  • Weakened immune system
  • Development of stereotypies or expression of other abnormal behaviors

These are just some of the negative effects stress can have on horses. If you suspect your horse is suffering from stress that is detrimental to their health and wellbeing, it is always advisable to discuss this with your veterinarian. They can conduct a diagnostic exam and offer potential treatment options.

How Can We Best Manage Stress in Our Horses?

In recognizing that our horses will experience stress in their day-to-day lives, there are steps we can take to help them. The best advice for managing a horse’s stress level is to identify the cause and take steps to either eliminate the stressor or reduce its severity. However, in many situations, a stressor cannot be eliminated and the horse will need additional support.

One very important approach to supporting our horses and stress is through dietary management. Because acute and/or chronic stress can cause a variety of digestive disorders or impact their overall health, ensuring a horse is meeting their daily nutrient requirements is vital. Provide free-choice access to clean and fresh water, ensure your horse is receiving adequate amounts of quality forage (hay/pasture) and provide an appropriate, fortified feed and/or ration balancer to fill in the nutrient gaps not met by your forage. Ideally, the feed or ration balancer would be fortified with quality pre- and probiotics.

We have previously published many articles that address topics that help horses withstand stress. Here are some that are worthwhile to review:

These articles highlight some of the different circumstances and management situations that can lead to stress in our horses. They detail some of the more important nutrients our horses need and the management steps we can take to support their health and wellbeing.

Take Home Message

Our horses experience stress each and every day. Many stressors are acute and short-term events. However, others can be longer-lasting and chronic. Both can have impacts on a horse’s health. However, through careful management and proper diets, horses are better able to withstand stress and live healthier and happier lives. Please contact us for a free, personalized feeding plan or for any questions you may have.

Article By: Chris Mortensen, Ph.D.
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