Q: My horse has been diagnosed with COPD. How does treatment for respiratory problems work, and will it limit what he is able to do?

A: Chronic obstructive pulmonary disease (COPD), also known as recurrent airway obstruction (RAO) or, most recently, equine asthma, occurs when a horse inhales an allergen. This causes the airways to narrow, go into spasm and produce inflammatory cells and mucus.

Treatment should be aimed at reducing airway spasm and inflammation through the use of bronchodilator drugs (that dilate the airways) and steroidal anti-inflammatories (that reduce inflammation generally). These medications may be delivered orally or via inhalation. Inhalatory drugs consist of metered dose inhalers (MDI), nebulisers or soft mist inhalers. Mucolytics can also be prescribed to break up mucus that builds up in the airways.

It’s also important to address the horse’s environment. Many cases of asthma occur following dust inhalation, be it from a dusty stable environment or dusty forage. This means you need to consider the following:

• Using hypoallergenic bedding
• Improving ventilation by opening windows and doors
• Reducing dust in the forage through soaking or steaming hay, or feeding haylage

If asthma is diagnosed quickly and the horse responds well to the suggested treatment and management methods, he’s likely to be able to return to his normal levels of exercise. Problems only tend to arise in those cases that are difficult to control and those who require ongoing drug therapy.