Is your horse's coughing starting to make you worry? Like humans, horses cough to dispel mucus, dust or foreign matter from their airways. Every horse coughs now and then, and it's usually no reason to be concerned. When a cough is severe or persistent, though, it could be a sign of an underlying health issue. Learn how to look for possible causes of your horse's cough, how to care for your horse's respiratory health, and when you should seek veterinary treatment.

Other Signs To Watch For?
Concurrent symptoms can sometimes hint at why your horse is coughing. A fever can indicate that your horse has an infection or a tumor. Your horse's temperature should be about 99-101°F. A reading higher than 101.5°F indicates that your horse needs immediate veterinary care.
Also check for nasal discharge - does your horse have a runny nose? Thick, green or yellow mucus usually indicates a viral or bacterial infection, while clear discharge is typically caused by irritation or allergies. Also take note if the discharge is bloody, or only comes from one nostril - usually caused by an obstruction like a foreign object or a tumor.
Gently check your horse's lymph nodes for swelling. You can find them under each side of the jaw. Swollen lymph nodes, paired with a cough and thick nasal discharge, are a common sign of equine distemper, often known as strangles, a highly contagious bacterial infection that spreads between horses through direct contact. Horses typically recover from strangles in a few weeks with veterinary treatment.

When Is Your Horse Coughing?
Take note of patterns in your horse's coughing episodes. When, and where, do they occur? If your horse only coughs at the start of exercise, it's likely just "warm up coughs" This is when your horse clears their throat as they start to get moving. Exercise stimulates your horse to inhale deeply, which can cause them to expel any excess mucus in their airways. In most cases, warm up coughs are normal. If the cough persists beyond the start of exercise, or seems severe, or accompanied by other symptoms, you may need to talk to your vet.
Does your horse cough when they're outdoors? Or does it seem to happen more often in the stable? Or only in the arena? Environment-related coughs are typically caused by mold, dust, or another airborne allergen. Your vet can use an anti-inflammatory medication to control your horse's symptoms. Meanwhile, you can reduce your horse's exposure to irritants to make sure those symptoms do not come back. Coughing triggered by airborne allergens is often attributed to ROA or IAD, two conditions that are similar to asthma in people.

ROA and IAD - What's The Difference?
Two common causes of chronic coughing in horses are Recurrent Airway Obstruction (RAO, also known as Chronic Obstructive Pulmonary Disease [COPD] or heaves) and Inflammatory Airway Disease (IAD).
RAO is more common in older horses. It's typically caused by an allergy to mold or dust. A horse with RAO will often refuse exercise, may struggle to breathe at rest, and of course, cough frequently.
IAD is usually seen in young horses. You'd see symptoms similar to RAO, which can make the two conditions hard to distinguish, but the biggest difference is, with IAD, your horse will not experience labored breathing while at rest.
RAO and IAD are treated in similar ways, though you'll need your vet to make a formal diagnosis. Once your vet determines the problem, they'll use medication like Ventipulmin Syrup to help relax the muscles in your horse's airway and reduce mucus thickness so they can breathe more easily.
Then, you can work with your veterinarian to determine the likely trigger for your horse's respiratory flare-ups. You may need to make dietary changes and manage their environment to prevent symptoms from coming back.

Preventing Coughing In Horses
Reducing allergens and irritants in your horse's environment can greatly reduce their cough. Once your horse's symptoms are under control with the help of treatment from your vet, you can work on improving the air quality in your horse's stall.
A common source of dust and mold is hay. Feed a high quality hay, and store it away from where your horse is stabled. It can be helpful to soak hay, just be sure to drain off the water before feeding. Hay can also be steamed using a hay steamer, which effectively kills mold, fungus, mites, and bacteria.
Fresh air is crucial to your horse's respiratory health. If possible, choose a stall that's well-ventilated, and air it out often, especially when you clean. Turn out your horse to pasture as much as you can.
Your horse's bedding needs to be absorbent to reduce ammonia build-up, yet dust-free. The best choice depends on what you can find locally, and what is affordable. Straw is not recommended for horses with respiratory issues. Paper shavings, peat moss, compost and wood pellets are good alternatives to straw.
Clean your horse's stall often to control allergens and irritants. Make sure to turn out your horse while you are cleaning to limit their exposure to allergens that you may rake up.

How Vets Diagnose And Treat Coughing
In some cases, your veterinarian may be able to make a diagnosis based on your horse's clinical signs. However, coughing is a common symptom across many different conditions, so your vet may need to do some tests to see what is truly causing it.
Bronchoalveolar lavage (BAL) or "lung wash" is done to see what's going on. This simply means that a small amount of sterile saline is pumped into the part of one of the lungs, and then suctioned out so your vet can assess any dust particles, mold spores or bacteria that could be making your horse cough.
Depending on the cause of your horse's coughing, your veterinarian may recommend environmental, dietary and exercise changes. If your horse has a bacterial infection, or a viral infection with a secondary bacterial infection, they may need antibiotics.
It's especially important to act fast if your horse might have a viral or bacterial infection that could be contagious to other horses. Most health conditions that cause coughing can be treated, managed or cleared up relatively quickly with your vet's help.