Alar fold resection in 25 horses: Clinical findings and effect on racing performance and airway mechanics (1998-2013).

Objective: To report clinical findings and performance in horses in which alar fold collapse (AFC) had been diagnosed and surgically treated and to assess form and degree of respiratory obstruction.

Study Design: Retrospective case series.

Animals: Twenty-one standardbreds, 2 coldblooded trotter racehorses, 1 thoroughbred, and 1 Icelandic horse.