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Equine asthma: does my horse have asthma?

Equine asthma is an incurable and progressive condition. If left untreated, it can lead to scarring within the horse’s lungs.

But it’s not all bad – while asthma can’t be cured, it can be managed successfully with the right treatments and lifestyle adjustments.

Let’s take a closer look at equine asthma, how to spot it, and how to manage your horse’s symptoms.

What exactly is equine asthma?

In its early stages, equine asthma is a reversible narrowing of the airways. It’s usually caused by allergies, most commonly to dust or pollen.

The allergic reaction causes the production of fluid within the small airways, as well as thickening of the walls. As a result, the horse must breathe harder and faster. They often develop a cough as they try to clear the mucus.

Signs to watch out for

  • Coughing
  • Nasal discharge
  • Quick or heavy breathing
  • Difficulty exercising
  • A ‘heave line’ appearing (a line of visible abdominal muscles, caused by coughing)
  • Respiratory distress (they could suffer an acute attack if they’re repeatedly exposed to the allergen)

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How will the vet diagnose asthma?

First, the vet will take a full history of your horse and examine them thoroughly.

They’ll then perform an endoscopy, where a camera on the end of a flexible cable goes up the horse’s nose and down into their airways. To make sure it’s definitely asthma your horse is suffering from, and not another respiratory condition, the vet will take samples from the horse’s wind pipe and lungs.

Once they have the results, the vet will decide on a suitable treatment.


Treatment will depend on the severity of the horse’s symptoms.

If a case is caught early enough, keeping the horse on a ‘dust-free’ management system may suffice. This includes:

  • Avoiding the allergen that’s causing the reaction
  • Changing bedding to shavings or paper
  • Soaking or steaming hay
  • Dampening hard feed
  • Keeping stables well-ventilated

In more severe cases, your horse may need medical treatment. This can include an intravenous steroid injection, steroid powders and dilation of the airways.

When it comes to controlling your horse’s asthma, however, taking care of their living environment is very important.

Because the treatments needed can vary from case to case, it’s crucial to contact your vet for expert advice if you spot any of the symptoms listed above.

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Need more info?

For more help and advice on equine asthma, or any other aspect of your horse’s welfare, have a chat with your local vet.

Find your nearest vet using our Find a Vet page, or speak to a vet online using Online Vets.