A horse’s respiratory system works hard every day, filtering enormous amounts of air while delivering oxygen to the body. But seasonal changes, dusty barns, mold spores, pollen, smoke and poor ventilation can all place additional stress on the airways.

For horse owners interested in natural approaches, certain herbs have traditionally been used to support comfortable breathing, healthy mucus production and normal airway function. Thyme, elecampane and licorice are among the herbs commonly included in equine respiratory formulas.

However, herbs should be viewed as supportive tools—not substitutes for diagnosing and treating respiratory disease. Equine asthma, respiratory infections and other airway conditions can require veterinary assessment and targeted treatment. Environmental management, particularly reducing exposure to respirable dust and other airborne irritants, remains one of the most important components of respiratory care.

Seasonal Respiratory Challenges for Horses

Respiratory challenges can occur throughout the year, but certain seasons can create additional concerns.

In spring and summer, pollen, insects, wildfire smoke and changing pasture conditions may contribute to respiratory irritation. In fall and winter, horses often spend more time indoors and rely more heavily on stored forage. That can increase exposure to dust, mold spores and other airborne particles.

Stabling itself isn’t necessarily the problem. The issue is often air quality within the stable environment. Hay, bedding, manure, arena footing and inadequate ventilation can all contribute to airborne particles.

Horses with equine asthma can be particularly sensitive to these environmental triggers. According to the Merck Veterinary Manual, equine asthma is associated with airway inflammation and hypersensitivity to allergens such as dust, mold and other organic particles. Environmental management is considered a cornerstone of treatment.

If your horse develops persistent coughing, nasal discharge, increased breathing effort, poor exercise tolerance or difficulty breathing at rest, don’t assume the problem is simply seasonal allergies. Respiratory disease can have infectious, inflammatory and environmental causes, and veterinary diagnostics can help determine the appropriate approach.

Understanding Equine Airway Health

Healthy airways have several important jobs. They warm and humidify incoming air, trap particles in mucus and use natural clearance mechanisms to remove unwanted material.

The respiratory tract is therefore constantly interacting with the horse’s environment.

When excessive dust, mold spores or other irritants are inhaled, they can contribute to airway inflammation. Repeated exposure may be particularly problematic for horses prone to inflammatory airway disease or equine asthma.

This is why respiratory support should begin with the environment.

Before adding a respiratory supplement, look at:

• Hay quality and storage
• Dust levels in the barn
• Bedding choice
• Stable ventilation
• Indoor arena conditions
• Turnout opportunities
• Smoke and outdoor air quality
• Exercise intensity during poor air-quality conditions

For more information on protecting your horse’s lungs from environmental irritants, read Equine Wellness Magazine’s article on Smoke, Dust & Air Quality: Protecting Equine Lungs.

1. Thyme

Thyme (Thymus vulgaris) has a long history of traditional use for respiratory health. It contains aromatic compounds, including thymol, and is commonly found in herbal respiratory formulas.

In natural equine care, thyme is traditionally used to support:

• Normal mucus clearance
• Comfortable breathing
• Healthy respiratory secretions
• Normal microbial balance
• A healthy response to occasional airway irritation

There is some equine research involving thyme-containing preparations. A small study involving five horses with recurrent airway obstruction evaluated a preparation containing thyme and primula. Some measures of lung function improved, although important clinical measures did not show significant improvement. Because the study was very small, it shouldn’t be interpreted as proof that thyme alone treats equine respiratory disease.

Another small pilot study evaluated an herbal combination containing thyme, licorice and several other herbs in horses with recurrent airway obstruction. The researchers found no statistically significant improvement in the measured respiratory parameters, although some trends warranted further investigation.

In other words, thyme is promising as a complementary herb, but the evidence in horses remains limited.

2. Elecampane

Elecampane (Inula helenium) is another traditional respiratory herb. The root has historically been used in herbal medicine to support the respiratory tract and normal mucus clearance.

Elecampane is commonly included in natural respiratory formulas intended to support:

• Healthy mucus production and clearance
• Normal respiratory secretions
• Comfortable breathing
• General airway wellness

Its traditional use is well established in herbal practice, but controlled research specifically evaluating elecampane for respiratory disease in horses is limited.

That distinction matters.

An herb can have a long history of traditional use without having the same level of clinical evidence available for a conventional veterinary medication. For that reason, elecampane is best considered a complementary respiratory-support herb rather than a treatment for diagnosed respiratory disease.

3. Licorice: Useful, But Use With Caution

Licorice root (Glycyrrhiza glabra) has traditionally been used to soothe irritated mucous membranes and support respiratory comfort. It is frequently included in herbal blends for cough and respiratory wellness.

However, licorice deserves more caution than some other herbs.

Licorice contains glycyrrhizin, a compound that can produce significant effects when consumed in excessive amounts or for prolonged periods. Potential concerns include effects on fluid and electrolyte balance, blood pressure and cardiovascular function.

Canadian regulatory guidance for veterinary health products specifically warns against oral licorice use in animals with heart or kidney disease, advises against long-term use unless directed by a veterinarian, and cautions against combining it with other drugs unless directed by a veterinarian.

That makes licorice an herb to use intentionally rather than indefinitely.

If your horse receives prescription medications, has heart or kidney problems, is pregnant, or has another underlying condition, discuss licorice with your veterinarian before using it.

Herbs Are Only One Piece of the Respiratory Picture

It can be tempting to look for a single herb that will help a horse breathe more comfortably. But respiratory health is considerably more complex.

One small equine study evaluating an herbal combination containing thyme, licorice, garlic, white horehound, boneset, aniseed, fennel and hyssop found no statistically significant changes in the primary respiratory measurements. This illustrates an important point: traditional use and plausible mechanisms do not necessarily translate into proven clinical effectiveness in horses.

Herbs may have a place in an integrative wellness plan, but they should complement—not replace—environmental management and appropriate veterinary care.

Dust and Mold Management Comes First

If you want to support your horse’s respiratory health naturally, start with the air your horse breathes.

Reducing respirable dust is one of the most important steps owners can take. Common sources include hay, bedding, manure, arena footing and dust generated during barn cleaning.

Consider these practical strategies:

Improve ventilation

Fresh air and good ventilation help remove airborne contaminants. Stalls should have adequate airflow without creating uncomfortable drafts.

Evaluate your hay

Hay can contain dust, mold spores and other particles capable of irritating the respiratory tract. Store hay in a dry environment and inspect it regularly for musty odors, visible mold or excessive dust.

For susceptible horses, soaking or steaming hay may reduce respirable particles, although the most appropriate forage strategy depends on the individual horse.

Choose lower-dust bedding

Some bedding materials generate considerably more airborne particles than others. Consider lower-dust alternatives and avoid unnecessary disturbance of bedding while horses are nearby.

Turn horses out during dusty chores

Sweeping, blowing aisles and cleaning stalls can temporarily increase airborne particles. Whenever possible, keep horses away from these activities.

Keep hay and feed away from the breathing zone

Feeding methods can influence how much dust a horse inhales. Avoid practices that cause large amounts of dust to become airborne directly in front of the horse.

Watch outdoor air quality

Respiratory management isn’t limited to the barn. Wildfire smoke, agricultural dust and other outdoor pollutants can also affect horses.

When air quality is poor, consider reducing strenuous exercise and providing access to cleaner air.

Nutrition and Immune Support

A respiratory-support program should also consider the horse’s overall nutritional status.

A balanced diet provides the protein, vitamins, minerals, fatty acids and energy needed for normal immune and tissue function. That doesn’t mean adding a long list of supplements.

Instead, begin with the basics:

• Provide adequate, good-quality forage.
• Make dietary changes gradually.
• Ensure constant access to clean water.
• Address known nutrient deficiencies.
• Maintain an appropriate body condition.
• Support digestive health.
• Provide appropriate exercise when air quality permits.

Nutrition cannot prevent every respiratory condition, but it provides the foundation for normal immune function and whole-horse wellness.

For more information, see Equine Wellness Magazine’s Supporting Equine Immunity Before Cold Season, which explores the relationship between nutrition, gut health, environmental management and seasonal wellness.

What About Herbal Respiratory Supplements?

If you are considering an herbal respiratory supplement for your horse, look beyond the ingredient list.

Ask:

What is the purpose of each ingredient?
A quality product should clearly identify its ingredients and intended use.

Is there evidence in horses?
Research in humans or laboratory animals doesn’t automatically mean an ingredient has been proven effective in horses.

Are the amounts disclosed?
Transparent dosing information makes it easier to evaluate a product and discuss it with your veterinarian.

Could it interact with medication?
Some herbs can interact with medications or may not be appropriate for horses with certain medical conditions.

Is the horse competing?
Competition horses may be subject to medication and prohibited-substance regulations. Natural does not automatically mean competition-safe.

Is there an underlying respiratory problem?
Supplements should never be used to mask persistent coughing, abnormal breathing or declining performance without investigating the cause.

When to Call Your Veterinarian

Occasional coughing isn’t necessarily an emergency, but persistent or worsening respiratory signs deserve attention.

Contact your veterinarian if your horse develops:

• Persistent or frequent coughing
• Nasal discharge
• Increased respiratory rate
• Noisy breathing
• Reduced exercise tolerance
• Increased breathing effort
• Recurrent respiratory flare-ups
• Fever or depression
• Difficulty breathing at rest

Labored breathing at rest is particularly important and should be evaluated promptly.

Respiratory infections can also spread between horses. If several horses develop respiratory signs, or if respiratory symptoms are accompanied by fever, veterinary assessment and appropriate biosecurity measures become especially important.

Creating a Natural Respiratory Wellness Plan

The best natural respiratory-support strategy isn’t necessarily the one with the most herbs.

Instead, think about the whole respiratory environment.

Start by improving air quality and minimizing dust and mold. Provide appropriate forage and balanced nutrition. Encourage healthy movement and turnout when conditions permit. Monitor seasonal triggers and outdoor air quality. Then, if appropriate, consider carefully selected herbs such as thyme or elecampane as complementary support.

Licorice may also have a role in some formulations, but because of its potential safety concerns and medication interactions, it deserves particular caution.

Most importantly, don’t let the appeal of natural remedies delay diagnosis. Equine asthma, infection and other respiratory disorders can require targeted veterinary treatment.

The Bottom Line

Thyme, elecampane and licorice are among the herbs traditionally used for respiratory support in horses, but scientific evidence for their effectiveness in equine respiratory disease remains limited.

The strongest foundation for healthy airways is still good environmental management: clean forage, low-dust bedding, adequate ventilation, reduced exposure to mold and airborne irritants, and appropriate turnout.

Herbs can be part of an integrative approach, but they work best when they’re considered one piece of a larger respiratory wellness plan.