ASTHMA/RAO/COPD

Winter is often when I see more cases of equine asthma. Chronic obstructive pulmonary disease (COPD; also known as recurrent airway obstruction (RAO) and equine asthma), occurs when inhaled allergens initiate a cycle of airway constriction and airway inflammation. Two forms commonly occur — summer asthma secondary to pollen, and the more renowned form triggered by dust. The latter occurs throughout the year, but is prevalent in winter when horses spend more time stabled.

Affected horses present with clinical signs of varying severity.

Some merely have a history of poor performance or a mildly increased respiratory (breathing) rate, whereas others are more severely affected and present with respiratory distress.

Diagnosis is often based on the presence of clinical signs, but is confirmed following respiratory tract endoscopy and airway fluid samples.

With dust-induced asthma, management changes are of paramount importance. The affected patient should be out, breathing fresh air as much as possible. While stabled, minimising dust in the patient’s environment is crucial.

I advise using dust-free bedding in the form of paper, cardboard or dustextracted shavings. Bedding should be laid without the horse present, and small amounts replaced daily.

Cobwebs should be hoovered from the stable quarterly and grooming should also take place outside to minimise stable dust. If feeding hay, a hay steamer is ideal; otherwise, hay should be thoroughly soaked and fed prior to drying out.

Sometimes, management changes alone aren’t sufficient and medication is required. Airway inflammation is slow to resolve, and treatment may be required for a period of months. Drugs can be administered orally or by the inhalatory/nebulised routes.