Inflammatory airway disease

Veterinary advice should be sought before applying any treatment or vaccine.

Inflammatory Airway Disease

Small Airway Inflammatory Disease, Lower Airway Disease, Bronchiolitis, Lower Respiratory Tract Inflammation (LRTI)

Inflammatory airway disease (IAD), also referred to as lower respiratory tract inflammation (LRTI), is a common cause of poor respiratory health and reduced performance; affecting up to 50 percent of athletic horses, across all equestrian disciplines. IAD is characterized by airway inflammation and airway hyperresponsiveness, in addition to exercise intolerance, nasal discharge, variable coughing, and increased mucus in the airways.

IAD is considered to be a milder form of equine respiratory inflammatory disease, in which no respiratory effort is apparent while the horse is at rest. Both IAD and recurrent airway obstruction (RAO) also known as 'heaves', are caused by exposure to particulate matter. However IAD can affect horses of any age and is associated with more subtle clinical signs and RAO occurs in more mature, older horses with more obvious clinical signs.


Exercise intolerance at high speeds
Chronic cough, common during exercise or eating
Nasal discharge
Delayed recovery from exercise
Exaggerated respiratory effort during work
Normal respiratory rate at rest


  • History
  • Clinical signs
  • Physical exam
  • Endoscopy
  • Tracheal aspiration/BAL
  • Radiography
  • Pulmonary function testing



Environmental modificationProvided with good ventilation, low-dust bedding and hay
Pharmacological treatmentsystemic or inhaled corticosteroids and bronchodilators
Omega-3 polyunsaturated fatty acids (PUFA)Containing 1.5-3 g docosahexaenoic acid (DHA) for 2 months provides an additional benefit to a low-dust diet


  • Limiting exposure to dust
  • Maximizing turnout
  • Soaking hay
  • Improving ventilation in the stable
  • Increased turnout
  • Changing bedding material to one that generates less dust
  • Reduced activity in the barn


Scientific Research

General Overviews

Clinical Trials

Risk Factors

  • Stabled horses, especially those living in a dusty environment with poor ventilation.