Allergies in Horses: Causes, Symptoms, and Treatment

Allergies in horses are common but can cause discomfort and even serious health problems. Horses can develop allergies to a variety of substances, including pollen, dust, mold, and certain types of feed. Identifying and managing allergies in horses is essential to maintaining their health and well-being.

Symptoms of allergies in horses may include coughing, sneezing, nasal discharge, skin irritation, and difficulty breathing. In severe cases, allergies can cause anaphylaxis, a potentially life-threatening allergic reaction. It’s important to be aware of these symptoms and seek veterinary care if necessary.

Preventing and managing allergies in horses can involve a variety of strategies, including environmental management, dietary changes, and medication. By working with a veterinarian and implementing appropriate management practices, you can help your animals live healthy and comfortable lives despite allergies.

Understanding Allergies in Horses

An allergy is an abnormal response of the immune system to a foreign substance, also known as an allergen. In horses, allergens can be found in various sources such as food, bedding, and environmental factors.

Allergic reactions in horses can range from mild to severe, and the symptoms can vary depending on the allergen and the individual horse. Some horses may develop skin rashes, while others may experience respiratory problems.

The most common allergens that affect horses include dust, mold, pollen, insect bites, and certain foods. Horses that are allergic to dust and mold may develop respiratory issues such as coughing and wheezing. Pollen allergies may cause skin rashes and itching. Insect bites can cause swelling and irritation, while certain foods can trigger digestive problems.

Diagnosing an allergy in a horse can be challenging, as the symptoms can be similar to those of other health issues. A veterinarian may perform skin tests or blood tests to identify the allergen and determine the best course of treatment.

Treatment for allergies in horses typically involves avoiding the allergen or reducing exposure to it. Medications such as antihistamines and corticosteroids may also be prescribed to alleviate symptoms. In severe cases, immunotherapy may be recommended to desensitize the horse’s immune system to the allergen.

Common Allergens in Horses

Horses can develop allergies to a variety of substances, including dust, pollen, hay, mold, food, bacteria, insects, pollens, molds, hay dust, airborne allergens, spores, fungal, ammonia, culicoides, wool, leather, fungi, dust mites, grains, and fungal spores.

Dust can come from a variety of sources, including hay, shavings, and soil. 

Horses can also be sensitive to a variety of different types of pollen, including tree, grass, and weed pollen.

More From Savvy Horsewoman:  Horse Cost Case Study: March 2020

Mold is often found in damp hay, bedding, and soil. 

Food allergies can also occur in horses, and some common culprits include alfalfa, oats, and sweet feed.

Insects, particularly culicoides, which are small biting midges, can cause allergic reactions.

Airborne allergens, such as spores and fungal particles, can also cause allergic reactions in horses.

It’s important to be aware of the common allergens that can affect your horses and to take steps to minimize their exposure to these substances. This may involve using dust-free bedding, avoiding certain types of feed, and providing ample ventilation in stables and barns.

Symptoms of Allergies in Horses

Allergies in horses can manifest in a variety of ways, and it can be challenging to diagnose them accurately. However, some common symptoms can indicate an allergic reaction in horses.

Skin Allergies

Horses with skin allergies may develop hives, also known as urticaria, which are raised, itchy bumps on the skin. They may also experience itching, dermatitis, pruritus, or hair loss. These symptoms can occur anywhere on the body, but they are most commonly seen on the neck, chest, and belly.

Respiratory Allergies

Respiratory allergies in horses can cause coughing, wheezing, nasal discharge, and difficulty breathing. Inflammation and airway obstruction can also occur, leading to conditions such as asthma, heaves, and recurrent airway obstruction. These symptoms are often worse during exercise or when the horse is exposed to allergens such as dust, mold, or pollen.


In severe cases, horses can experience anaphylaxis, a life-threatening allergic reaction that can cause shock, collapse, and even death. Anaphylaxis is usually triggered by insect bites, medications, or certain foods.

Diagnosis of Allergies

Diagnosing allergies in horses can be challenging as the clinical signs can be vague and non-specific. It is important to involve a veterinarian who has experience in diagnosing equine allergies.

The first step in diagnosing allergies is to perform a thorough physical exam and history taking. The veterinarian will ask questions about the horse’s environment, diet, and medical history. They will also look for any signs of skin irritation, respiratory distress, or other clinical signs that may indicate an allergic reaction.

Allergy testing may be recommended to identify the specific allergens that are causing the horse’s symptoms. There are several types of allergy testing available, including intradermal skin testing, serum testing, and mucosal testing. Intradermal skin testing is considered the gold standard for diagnosing equine allergies, as it has a high level of accuracy and can identify both environmental and food allergens.

More From Savvy Horsewoman:  8 Tips for Feeding Your Easy Keeper

Once the allergens have been identified, the veterinarian will work with the owner to develop a management plan that reduces the horse’s exposure to the allergens. This may involve changes to the horse’s diet, environment, or medication.

In some cases, a challenge test may be performed to confirm the diagnosis of an allergy. This involves exposing the horse to the suspected allergen and monitoring their response.

Treatment and Management of Allergies

When it comes to treating and managing allergies in horses, there are several options available. The right treatment will depend on the severity of the allergy and the individual horse’s response to different therapies.


Medications such as antihistamines, steroids, and corticosteroids can be effective in relieving allergy symptoms. Dexamethasone and prednisolone are two commonly used corticosteroids that can help reduce inflammation and swelling associated with allergies.


Supplements such as omega-3 fatty acids and probiotics may also be beneficial in managing allergies. Omega-3 fatty acids have anti-inflammatory properties and can help reduce the severity of allergic reactions. Probiotics can help improve gut health, which may play a role in reducing allergic reactions.


Shampoos containing ingredients such as oatmeal, aloe vera, and chamomile can help soothe itchy skin and reduce inflammation. Regular bathing can also help remove allergens from the horse’s coat and skin.

Allergy Shots

Allergy shots, also known as immunotherapy, can be effective in reducing the horse’s sensitivity to allergens over time. This treatment involves injecting the horse with small amounts of the allergen to build up immunity.

Prevention of Allergies in Horses

Preventing allergies in horses requires a combination of management and environmental changes. Proper horse care, including regular grooming, can help reduce the risk of allergies. Pasture management is also important, as horses can develop allergies to certain types of grasses and plants. Equine asthma can also be a trigger for allergies, so it is important to manage this condition with veterinary guidance.

Bedding is another important factor to consider when preventing allergies in horses. Dusty or moldy bedding can trigger allergies, so it is important to use clean and dust-free bedding. Insect bites can also cause allergies in horses, so it is important to use fly sprays and other insect repellents to protect horses from biting insects. Sweet itch, caused by biting midges, can also be a trigger for allergies, so using fly sheets and other protective gear can help prevent this condition.

Saddle pads and blankets can also be a source of allergens, so it is important to keep these items clean and free from dust and mold. Barns should also be kept clean and well-ventilated to reduce the risk of allergies. Proper nutrition is also important in preventing allergies, as a balanced diet can help boost the immune system.

More From Savvy Horsewoman:  Recognizing Symptoms of COPD in Horses

Vaccines can also be used to prevent allergies in horses. Desensitization therapy can also be effective in reducing the severity of allergies. Trial or elimination diets can help identify food allergies in horses, which can then be managed through dietary changes.

Frequently Asked Questions

What are common allergens for horses?

Horses can be allergic to a variety of substances, including dust, mold, pollen, insect bites, and certain foods. Some horses may also develop allergies to bedding materials, such as straw or shavings.

How can you tell if a horse is having an allergic reaction?

Symptoms of an allergic reaction in horses may include hives, swelling, difficulty breathing, coughing, and nasal discharge. In severe cases, the horse may go into shock or develop anaphylaxis, which can be life-threatening.

What are the symptoms of skin allergies in horses?

Skin allergies in horses may present as itching, scabs, hair loss, or a rash. The affected area may be red or inflamed, and the horse may rub or bite at the area to relieve the itching.

What are some treatments for allergies in horses?

Treatment for allergies in horses may include antihistamines, corticosteroids, or allergy shots. In addition, identifying and removing the source of the allergen can help to prevent future reactions.

Can horses have seasonal allergies?

Yes, horses can develop seasonal allergies, particularly in the spring and fall when pollen counts are high. Symptoms may include runny nose, coughing, and itchy eyes.

Are there any precautions you can take to prevent allergies in horses?

To prevent allergies in horses, it is important to keep their environment as clean and dust-free as possible. This may include using low-dust bedding, avoiding exposure to mold and pollen, and providing a well-ventilated living space. In addition, feeding a balanced diet and maintaining good hygiene can help to support the horse’s immune system and reduce the risk of allergic reactions.

Leave a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.