It’s hot. You go for a ride, but your horse is lackluster. His nostrils are flared with heavier breathing, despite it being just a trail ride. His breathing has you concerned.
We frequently hear about breathing issues in the winter due to being kept in a stall, or in the spring, due to pollen. But why would we have breathing issues on these beautiful, but hot summer days?
◆︎ Symptoms of summer breathing issues:
➡ Exercise intolerance
➡ Coughing
➡ Flared nostrils
➡ Increased respiratory rate
➡ Labored breathing
◆︎ Factors affecting breathing in summer
◆︎ Heat and dehydration: Heat affects breathing in a couple of ways.
Excessive heat is devastating to the body. To maintain body temperature, the horse sweats, resulting in evaporative cooling. This involves the actual sweat from the skin, but the mechanism also involves the movement of fluids out of the circulatory system to the skin. The sweat loss can result in dehydration.
Additionally, the movement of fluids out of the circulatory system can result in decreased blood volume. This decrease in blood volume signals the body that there is a fluid loss. In the body’s attempt to conserve fluid, the urine becomes more concentrated, fluids move from the intestines back into the circulatory system, less fluid is made available to the mucus membranes. This may result in gums that are drier and tackier, as well as a thickening of mucus, especially in the mouth, nasal passages, and lungs. The thicker mucus in the lungs makes it more difficult to expel particles and irritants.
To exacerbate this loss of fluids, a horse may decline to drink because of the loss of electrolytes in the sweat, elevated temperature of the drinking water, or the cleanliness of the water.
Action items:
Action items include:
☛ Cooling the horse from excessive heat. This could include cold-water hosing or providing shade from the heat.
☛ Rehydrating the horse. Offering clean, cold water.
☛ Supplying electrolytes to support the horse because of previous losses in sweat.
☛ Supplementing N-Acetyl Cysteine to help thin the mucus in the lungs, making it easier to expel airborne particles.
◆︎ Humidity, plus airborne particles: Humidity, especially when coupled with heat, can cause bronchoconstriction. This can result in difficulty in breathing. It can be exacerbated by airborne particles, which get trapped on the vapor molecules. These particles can be from wild fire smoke, dust blown in from the trans-Atlantic Sahara Desert winds or elsewhere, or local pollutants. The bronchoconstriction plus the airway irritants can cause a horse to have labored breathing.
Action items:
For some, a barn with a dehumidifier can reduce the humidity in the air. However, for most, a climate-controlled barn is not an option. Steps that are available to the horse owner include:
☛ Anti-inflammatories: Steps to reduce airway inflammation may be helpful. This could be with supplements that have anti-inflammatory properties, such as Spirulina, Mov-Ease, Chondroitin sulfate, or MSM.
☛ Mucolytics: N-Acetyl Cysteine can thin the mucus, making it easier to expel airborne particles.
☛ Reduce the exposure to pollutants. Although this may be difficult, steps could include not working your horse when the humidity is high, or when air quality is poor. This is important because deep breathing draws air with pollutants deep into the lungs. Shallow breathing makes it more likely that the pollutants will be trapped in the mucus of the upper respiratory system.
Additionally, rinsing the hay to lower dust levels, or adding pellets or cubes to their diet may be helpful in reducing the exposure to airborne particles.
◆︎ Seek veterinary care
When supplements aren’t sufficient to support your horse’s breathing, veterinary care is prudent. Your veterinarian can make a diagnosis and prescribe a therapy that is appropriate. Examples of the further care could include antihistamines, corticosteroids, or bronchodilators. Your veterinarian can advise you as to the appropriate treatment plan.
◆︎ Recap:
With heat and humidity, hydration may be helpful, especially when your horse has additional electrolytes, such as Equine Electrolytes – IR Safe.
Anti-inflammatories may be helpful to support the horse’s breathing, such as Spirulina, Mov-Ease, Chondroitin sulfate, or MSM.
N-Acetyl Cysteine is a mucolytic and can help thin the horse’s mucus. Mucus that is thinner can better facilitate expelling airborne particles.
When additional support is needed, it’s prudent to seek veterinary care.
We do the best that we can do for our horses. Understanding potential breathing issues in summer is a part of that.
Disclaimer: Statements regarding dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease or health condition.
©Joan Kulifay, MSc. 2025