Equine Asthma aka Heaves

Equine Asthma aka Heaves

Whinny’s Wisdoms

Springhill Equine Veterinary Clinic

Hey everybody, Whinny here! This week we’re talking about breathing problems in horses. Equine Asthma, which is what we’re calling it now, has been known by several other names over the years. Some of the most commonly used terms were Heaves, Recurrent Airway Obstruction, and Inflammatory Airway Disease.

Equine Asthma is a disease primarily associated with lung inflammation. This lung inflammation results in the clinical signs that we observe with this disease, including coughing, mucous production, wheezing noises from bronchoconstriction, and a “heave line”. The heave line can be observed as an abdominal push near their flank area where they are exerting extra pressure to breathe. This is often accompanied by nostril flaring. As you can imagine, an Equine Asthma attack can be distressing for the horse and hard to witness for someone who is caring for them.

Springhill Equine Veterinary Clinic

            Diagnosing Equine Asthma can be done with a thorough physical exam. My veterinarians will listen to the lungs of a horse with their stethoscope for a high pitched “wheeze” noise. This noise in an otherwise healthy horse that has a cough is often enough to diagnose Equine Asthma. More complex cases may require a BAL (bronchoalveolar lavage) where my doc takes a sample of the lower airway and evaluates it for the presence of certain types of cells to confirm the diagnosis. 

            Equine Asthma is often triggered by different allergens. The biggest culprit for horses tends to be dust. Additionally, mold, pollen and other environmental allergens can play a role in triggering an acute asthma attack. Asthma often occurs seasonally, but some horses do need to be treated year round.

Whinny Wisdom: Donkeys are just as susceptible to Equine Asthma as horses are! Make sure you keep an eye on their breathing, and be ready to manage them and their environment the same way you would with your horse.

            Since there is inflammation in the lungs with Equine Asthma, the mainstay of therapy includes a very potent anti-inflammatory: dexamethasone. This is a steroid medication that can be given orally, intravenously or intramuscularly. Since we are often giving this medication daily, many owners prefer to give the medication orally (the horses also prefer this way). The biggest risk to steroid medications is laminitis or founder. Due to this risk, nebulized or inhaled versions of steroids may alternatively be used instead of dexamethasone to treat the condition. This may be recommended based on an individual horse’s concurrent risk factors for laminitis. Yet another good reason to keep your horse at a healthy weight!

            In an Equine Asthma attack, a rescue medication may be used for several days in a row to help open the lower airways in addition to the steroid therapy to reduce inflammation. This rescue drug is commonly called Ventipulmen, or clenbuterol. This medication may be recommended to have on hand depending on the horse’s response to steroids.

            Additionally, an antihistamine such as ceterizine (generic form of Zyrtec) or hydroxyzine may help reduce the number of acute episodes a horse may experience depending on the allergens that are causing the asthma in the patient. While these medications can help reduce the number of episodes, they do not provide the anti-inflammatory effects that a steroid can provide, so cannot be solely used for management. (If you read between the lines, it says: don’t do any of this without the guidance of your veterinarian!)

Springhill Equine Veterinary Clinic

            Finally, a key management factor is environmental management. This primarily focuses on reducing dust since this is often one of the main triggers for Equine Asthma. This can be accomplished by wetting any feed, both grain and hay. In more severe cases, some horses may not be able to consume hay due to the dust and allergens that are present. Hay steamers can also help in these situations as they reduce dust and kill mold spores and bacteria that may be present. Depending on the horse’s allergens, stabling time may need to be limited as the barn bedding can be dusty. If a horse with Asthma needs to be stalled, minimally dusty bedding such as hemp or flax should be selected. Straw should not be used as it often has a high level of dust and allergens. 

            Although it can be stressful to see your horse afflicted by Equine Asthma, it’s important to remember that treatment options are available to manage this condition and my docs here at Springhill Equine are ready to help. If you think your horse might be developing a breathing problem, give us a call at (352) 472-1620 to set up an evaluation.

Until next week,


P.S. Want more? Check out the podcast episode my docs did on airway issues in horses! You can listen to it right from your phone, and by the end you’ll know all about it!

Whinny’s Wisdoms is the official blog of Whinny the Clinic Mouse at Springhill Equine Veterinary Clinic in Newberry, Florida. If you liked this blog, please subscribe below, and share it with your friends on social media! For more information, please call us at (352) 472-1620, visit our website at SpringhillEquine.com, or follow us on Facebook!

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More Adventures of the Horse Doctor's Husband
Equine Asthma

Equine Asthma

Tuesdays with Tony

Wowza!! It has been a hot one this weekend. Hopefully you all made it through the long weekend. Who am I kidding? Of course you made it through the weekend, you had to in order to read my blog this week.  Luckily, my staff knew just what a scorcher it was going to be and left me and Teeny in the lovely air-conditioned office for the weekend. I spent my weekend getting caught up on my sleep and refreshing my memory about equine asthma.


Equine Asthma, COPD, Recurrent Airway Obstruction, Heaves, Inflammatory Airway Disease, which is it? Why can’t these humans pick a term and stick with it? Well, as I found out this weekend, there is a reason why it has so many different names. The current accepted term for equine airway disfunction is Equine Asthma. Subcategories of equine asthma include Inflammatory Airway Disease and Heaves/RAO. To break it down even further, Heaves/RAO can be divided into Pasture-associated and Barn-associated. So, how do we determine if your horse has Equine Asthma, and if they do, which form they have? That’s where my docs and I come in. I’m going to give you a brief overview of the different forms of Equine Asthma and if you have a concern about one of your horses, you’re going to call the clinic and schedule an appointment with one of my docs.


Inflammatory Airway Disease


IAD is a respiratory disease that typically affects younger horses. It is characterized by a lingering cough, poor performance, increased breathing efforts, and prolonged recovery after exercise. Some horses may have watery-to-white nasal discharge but will never develop a fever. What sets these horses apart from horses with Heaves is that they are normal at rest with no increased respiratory effort or rate. Their appetite and attitude remain unchanged at rest.


What do you do if you notice your horse showing any of these symptoms? First, you call my clinic and my docs will come out and perform a thorough physical examination. This may include a rebreathing exam where they place a bag over your horse’s nose and mouth. While your horse is staring at you like, “what the heck are they doing to me, mom?” my docs will be listening closely to your horse breathe. Once the bag is removed, they will continue to listen while monitoring how long it takes your horse to breathe normally again, as well as note any change in lung sounds or coughing. Depending on what is seen and heard on the physical exam, my docs may recommend you bring your horse to the clinic for further diagnostics.

 Springhill Equine Veterinary Clinic

When you bring your horse to the clinic there are a couple diagnostic tests we will perform. First, my docs will perform a Bronchoalveolar Lavage (BAL) where they will obtain samples from your horse’s airway to send to the lab and look for inflammatory cells. They will also perform an endoscope exam to the upper airway. A small camera is passed up your horse’s nose and into their trachea where they will look for excessive mucous buildup.  I sure hope my docs don’t ever try and stick anything up my nose. I can’t promise I won’t scratch anyone if they do!


Based on the diagnostic results, my docs will recommend certain treatments, including environmental changes. The goal of environmental changes is to reduce dust allergens. This can be accomplished by soaking hay and grain, and bedding horses on paper or wood shavings. Your horse should be out of the barn during cleaning and remain out for an hour after chores are complete. This will prevent them from breathing in excessive dust particles that may be floating about after cleaning is complete.


My docs may also recommend a course of systemic steroids to reduce inflammation in the airways. It has been shown that Omega-3 fatty acids help to reduce inflammation as well. I’m not convinced that horses will readily eat fish oil, but it sure sounds delicious to me! There are commercially-developed Omega-3 fatty acids that are more palatable to horses than straight fish oil. My docs may also recommend bronchodilators such as clenbuterol or albuterol which may come in oral or inhaled forms.


Luckily, if your horse is diagnosed with IAD, the prognosis of a full recovery if treated is excellent. If cats got IAD, I would just take it as my sign that I should never exercise again. Oh wait, I don’t currently exercise. I guess we will never know if cats get IAD.


Heaves/Recurrent Airway Obstruction


Unlike IAD, a horse with Heaves/RAO is not normal at rest. You may notice your horse breathing rapidly or with more effort. You may even hear them coughing more frequently. You may also notice nasal discharge along with exercise intolerance. Horses with Heaves will have the classic “heave line” at the bottom of their ribs due to increase in abdominal muscle mass from excess work performed in order to breathe. Some horses with Heaves may become in appetent, although why horses decide to stop eating is beyond me. The horses usually experience weight loss due to decreased feed intake. Similar to IAD, horses with Heaves will not typically have a fever.


You may recall I mentioned early on that there are two different types of Heaves, Barn-associated and Pasture-associated. Horses with Barn-associated Heaves spend the majority of their time kept in a stall where they are exposed to typical molds, dust and endotoxins in hay and straw. Horses with Pasture-associated Heaves typically reside in the Southeast and spend the majority of their time on pasture where they are exposed to inhaled allergens. Both types of Heaves result in lower airway inflammation, but exact factors causing the airway dysfunction is unknown.


Heaves is diagnosed by BAL and endoscopic examination. Radiographs and thoracic ultrasound are also useful diagnostic tools used to further characterize the inflammation in your horse’s lungs.


Treatment for heaves is similar to that of IAD. At the forefront of treatment is to reduce allergens by soaking hay and grain. It is also important to keep horses with heaves off of round bales as they are very high in endotoxic and organic dust. Horses with Barn-associated Heaves should be kept on pasture and horses with Pasture-associated Heaves should be kept stalled except in the winter months when allergens are low. Systemic steroids and bronchodilators are also recommended for horses with Heaves.


Now that you are an expert on Equine Asthma, if you are concerned that your horse may be showing any of these signs, be sure to contact me at the clinic and I will get you in touch with one of my docs.  We will get out to check on your horse as soon as possible.


Now it’s time for me to go back to enjoying the remainder of this holiday weekend in the cool AC. Take a moment to remember all those who have served our country and provided us with the freedom to nap all day.


Until next week,


Tuesdays with Tony is the official blog of Tony the Clinic Cat at Springhill Equine Veterinary Clinic in Newberry, Florida. If you liked this blog, please subscribe below, and share it with your friends on social media! For more information, please call us at (352) 472-1620, visit our website at SpringhillEquine.com, or follow us on Facebook!

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