Supporting Horse Calmness Under Anxiety Triggers

Horses are complex creatures with a variety of behaviors and responses. Of the 7.2 million horses in the United States, many will at some point display anxious behaviors. Understanding the systems that underpin your horse’s behavioral health can help you take appropriate steps to help your animal maintain a state of calm.

Table of Contents

1. The Equine Nervous System and Calmness
2. Interactions Within the Equine Nervous System
3. What Activates the Sympathetic Nervous System in Horses?
4. Maintaining Balance and Behavioral Health

The Equine Nervous System and Calmness

Despite their size and strength, horses are prey animals. In a fight-or-flight situation, they are predisposed to choose flight. This natural flight response may affect a horse’s calmness when it encounters anxiety triggers.

Two main nervous systems work together to balance equine behavior and control how horses respond to external triggers. The parasympathetic nervous system (PNS) stimulates regular body maintenance processes associated with eating, digesting and calmness. In a horse’s natural state of rest, the PNS is the main nervous system that is engaged. When a horse encounters a trigger, part of its endocrine response known as the sympathetic nervous system (SNS) releases stress hormones. This endocrine and nervous system response is responsible for the flight response in horses.

The PNS and SNS work together to promote normal horse behavior and calmness.

Interactions Within the Equine Nervous System

When a horse feels relaxed and safe, the parasympathetic nervous system slows down breathing and heart rate while increasing blood flow to the intestines, liver and the rest of the digestive tract. Horses in a PNS state look relaxed and at ease. Normal breathing, yawning and gut sounds will be visible.

The PNS is sometimes counteracted by the SNS, which governs the state of high alert that urges a fight, flight or freeze response in a horse. An engaged SNS heightens the senses, diverts blood to the muscles and increases blood pressure and breathing rate. Essentially, activation of the SNS prepares a horse to face or escape from danger.

The balance between the SNS and PNS is crucial to a horse’s behavioral health. Understanding the triggers for an activated SNS can help you maintain healthy behavioral responses in your horse.

What Activates the Sympathetic Nervous System in Horses?

Horses may experience an activated SNS from several different sources:

1. Transportation: In natural settings, horses spend up to two-thirds of their time moving. Standing for long periods in a vehicle can disrupt a horse’s normal routine.
2. Exertional rhabdomyolysis (ER): Under normal conditions, a horse’s heart and respiratory rate will slow after exercise. If cramping and muscle pain occur during this period, it can activate the SNS.
3. Oxidative stress: Normally, almost all the oxygen your horse consumes turns to water and carbon dioxide. A remaining 1-2% of unused oxygen forms reactive oxygen species (ROS), which can degrade proteins.
4. Cold stress: For each degree the ambient temperature falls below a horse’s critical temperature, the animal expends about 1% more energy.
5. Heat stress: When a horse exercises it can produce up to 50% more body heat, increasing sweat output and respiration rate.
6. Ulcer stress: In both an eating and resting state, a horse’s stomach produces acid. For this reason, ulcers can be common.

Maintaining Balance and Behavioral Health

Maintaining a balance between the SNS and PNS when triggers are present can promote healthy weight, metabolism and overall function in your horse. Taking a proactive approach for nervous system wellness is an important element in maintaining overall health:

1. Look for natural body language: In a resting state, a horse’s ears are turned out to the side and its head is lowered. A relaxed horse may also show a drooping lip, slack mouth or chewing when not eating. These behaviors indicate your horse’s PNS system is functioning and promoting calmness.
2. Establish a routine: A basic routine will go a long way in providing stability. A horse conditioned to expect feeding and exercise at certain times of day will spend more time in “rest and digest” mode.
3. Allow for locomotion: Before they were domesticated, horses evolved to be grazing animals. As a result, locomotion supports healthy digestion, respiration, metabolism and physical health. Giving your horse time and space to move while grazing can help satisfy this need.
4. Promote socialization: Horses have a natural instinct for social interaction over isolation. Providing socialization opportunities for your horse to be around other horses can promote overall wellness and behavioral health.
5. Pace changes appropriately: At some point, you will have to make changes to your horse’s routine. Carefully planning and pacing these changes helps maintain your horse’s expectations and overall behavioral health.
6. Provide proper nutrition: Ensure your horse gets the appropriate amount of carbs, protein, fats, vitamins and minerals to ensure healthy nutrition.

In many cases, a horse with a thoughtful routine and healthy diet will exhibit calmer behavior and react less drastically to anxiety triggers.