Inflammatory airway disease (IAD) is one of the most widespread conditions affecting horses
world-wide. Over-crowding, stabling conditions and exposure to irritants (such as bedding
dust) have been thought to contribute to the development of IAD. Since the majority of sport
horses in New Zealand are kept at pasture for prolonged periods, differing from intensive
stabling conditions seen in other countries, variations in the type and frequency of respiratory
pathologies might exist. In order to investigate this possibility, and determine the most
common respiratory conditions affecting horses requiring endoscopic examination, this
preliminary epidemiologic study was conducted. A retrospective analysis of 145 respiratory
endoscopies was conducted including examinations made at 2 veterinary clinics from June
2010 to October 2012. Respiratory endoscopies results were initially classified as normal or
abnormal. Abnormal results were further classified as: IAD, anatomical abnormalities,
intermittent airway obstruction, trauma, miscellaneous abnormalities. Presence of tracheal
secretions of any kind and quantity warranted classification as (IAD). Overall, 76.5% of the
animals requiring a respiratory endoscopy demonstrated abnormalities which justified the
examination: the majority of horses (42.7%) displayed some degree of IAD. Other common
findings included intermittent dorsal displacement of the soft palate (6.9%); bleeding in the
upper respiratory tract (3.45%), and laryngeal hemiplegia (15.2%). Inflammatory airway
disease (IAD) is one of the most widespread conditions affecting horses world-wide and it is
also prevalent in the population studied, despite different housing and managing practices
observed in New Zealand in comparison to other countries. Further studies are needed to
investigate subclinical abnormalities and the causes of the IAD in horses kept at pasture.