Equine Asthma

Heaves, recurrent airway obstruction (RAO), chronic obstructive pulmonary disease (COPD) and inflammatory airway disease (IAD) are all names for the same respiratory condition – equine asthma.

What is equine asthma?

Equine asthma is a respiratory condition that causes your horse's airways to become inflamed. The inflammation causes the lining of the lower airways to thicken and mucus to build, making it more difficult for your horse to breathe. It is triggered by environmental allergies such as dust, and it is not contagious to other horses.

As equine asthma is triggered by allergies, it's often worse during the summer months, but it can cause problems all year round. If your horse suffers with equine asthma, you can put steps in place to help manage their condition.

Equine asthma symptoms

Equine asthma can be mild to moderate or severe. Horses suffering with severe equine asthma may show signs of an increased effort to breathe, even while resting.

Signs of equine asthma include:

• coughing
• noisy breathing (wheezing)
• nasal flaring
• nasal discharge
• a reluctance to exercise or slow to recover after exercise
• fast respiratory rate

Signs of severe equine asthma include:

• increased respiratory effort while resting
• heave line

A heave line is a noticeable line that shows just behind your horse's rib cage. When horses put in extra work to exhale, their abdominal muscle becomes enlarged, causing a heave line to appear.

If you recognise any symptoms of equine asthma in your horse, book an appointment with your vet.

What causes equine asthma?

Equine asthma is caused by your horse's lungs overreacting to allergies in the environment. In most cases, these allergens can be found in your horse's stable or hay. They include:

• dust
• mould
• mites
• toxic gases like ammonia (caused by your horse's waste)
• bacteria
• pollen (which triggers a type of asthma called summer pasture associated severe equine asthma)

Equine asthma can also develop as a result of other respiratory illnesses, such as strangles or equine flu.

Diagnosing equine asthma

If your vet thinks your horse is suffering with equine asthma, they'll need to run some tests. This often includes an endoscopy of your horse's airways.

An endoscopy involves passing a thin and long tube with a small camera at the end through your horse's nostrils and into their windpipe. This allows your vet to examine your horse's respiratory system, looking for any abnormalities such as inflammation or mucus. Your horse will usually need to be sedated for this procedure.

Your vet will also be able to run tests to try and uncover the specific allergy that is causing equine asthma, allowing you to manage your horse's condition more effectively.

Treatment for equine asthma

In many cases, symptoms of equine asthma can be reduced by managing your horse's environment. Your vet will be able to create a tailored management plan with you, but it usually involves reducing dust, bacteria or ammonia in the air, or managing your horse’s exposure to pollen.

Alongside this, your vet may also prescribe anti-inflammatory medication to reduce the inflammation in your horse's lungs.

For more severe cases, bronchodilators may be needed, which is a medication that opens up your horse's airways and allows them to breathe easier. This can be given in your horse's feed, inhaled (using an inhaler) or given as an injection.

Managing your horse’s equine asthma

As equine asthma is triggered by environmental allergies, there are things you can do to help manage your horse's condition.

Turn your horse out regularly

If your horse suffers with equine asthma, it's important that they spend plenty of time in the fresh air. By turning your horse out regularly, their symptoms can be greatly reduced, as it allows them to spend time out of their stable and away from any dust.

If you're worried about your horse feeding on too much fresh grass, you can consider using a grazing muzzle, rather than limiting their time outdoors.

Choose a suitable bedding

Bedding can be a primary source of dust building up in your horse's stable. Opting for a dust-extracted bedding, such as wood shavings, can help to lessen your horse's symptoms.

Reduce ammonia in your horse's stable

Ammonia is a toxic gas with a pungent smell, that's caused when bacteria breaks down the chemicals (urea) in your horse's urine. Ammonia is a common trigger for equine asthma and can be reduced by keeping your horse's stable clean. Mucking your horse out daily can help with this.

It's also a good idea use a suitable and easy to clean flooring in your horse's stable. Rubber flooring can be a good option as it can be thoroughly sterilised, however it's important to make sure that it is fitted and sealed correctly. This will prevent urine from seeping under the mats where it's difficult to clean.

Take your horse out when sweeping their stable

Sweeping your horse's stable and mucking them out can disturb the dust, so it's best to remove your horse before you begin.

The dust can sit in the air for around 30 minutes, so keep the stable door and windows open and bring your horse back in once the dust has settled.

Soak or steam your horse’s hay

Hay or forage is an important part of your horse's diet, but it can be extremely dusty.

You can prevent this by soaking your horse's hay. This helps the particles of dust to stick to the hay, rather than being released into the air where your horse can breathe them in. The downfall is that soaking hay can cause the hay to lose some of its nutrients.

If you are worried about the loss of nutrients, steaming your horse's hay can be a better option. Steaming preserves the nutrients and can help to kill mould and bacteria.

Keep your horse's stable ventilated

Make sure that your horse's stable is well ventilated to help to reduce dust and mould in the air.

To do this, you'll need to let the fresh air in and allow the warm, stale air to escape. This can be achieved by keeping the stable door and windows open and making sure that the height of your horse's stable roof is suitable. A higher ceiling will allow for better ventilation and air flow.

Store hay away from your horse’s stable

To help reduce dust, it's a good idea to store hay or forage away from your horse's stable. Hay is one of the biggest causes of dust in your horse's environment, so storing it away from your horse can help to reduce the amount of dust that sits in the air.