Inflammatory Airway Disease of Horses

Abstract

The purpose of this consensus statement is to provide a review of current knowledge and opinions concerning inflammatory airway disease (IAD) and to help practitioners differentiate IAD from heaves (or recurrent airway obstruction; RAO) and other inflammatory respiratory diseases of horses.

Respiratory Disease

“…Using a consistent volume of infusate (300-500 mL of saline) and retrieving approximately 50% of that fluid may somewhat standardize the degree of sample dilution. 19 A thorough cytologic report of BAL fluid analysis should include both a differential cell count and a description of cellular morphology and a comment as to whether noncellular components were present in the sample. Cytospin preparations are useful to expedite performing the differential cell count, because adequate numbers of cells can be quickly and efficiently assessed.…”

What are the bacteria in the lower airways of athletic horses telling us?

“…Lower airway inflammation (LAI) is a common condition in racehorses (Wood and others 2005a, Allen and others 2006, Couetil and others 2007) and is associated with reductions in performance and alterations in pulmonary function (Couetil and Denicola 1999, Sanchez and others 2005). In resting horses, disease can either be subclinical (Richard and others 2010a) or result in mild clinical signs, such as coughing and nasal discharge (Couetil and others 2007).…”

“…In resting horses, disease can either be subclinical (Richard and others 2010a) or result in mild clinical signs, such as coughing and nasal discharge (Couetil and others 2007). …”

“…Inflammatory airway disease (IAD) has been defined as non-septic inflammation detected by cytological examination of bronchoalveolar lavage fluid or pulmonary dysfunction (Couetil and others 2007), while tracheal inflammation with or without association with an infectious agent has been termed ‘syndrome of tracheal inflammation’ (Richard and others 2010a) or ‘tracheal IAD (trIAD)’ (Cardwell and others 2011a, b). By attempting to distinguish between different forms of LAI in terms of location in the lower airways, better understanding of the aetiopathogenesis of the disease in athletic horses may be achievable.…”

“…While as yet incompletely determined, it can be concluded that the aetiopathogenesis of LAI, including the syndromes of IAD and trIAD/STI, is complex and may involve both infectious and non-infectious factors (Malikides 2003, Couetil and others 2007, Cardwell and others 2011a). Furthermore, predisposition to the disease may be influenced by the location and demographics of equine populations, and, as Cardwell and others (2013) have shown, ongoing epidemiological studies are critical for improving our knowledge of this multifaceted problem.…”