Respiratory sampling
Horses that were not racing or competing within 10 days following sampling were sedated with detomidine (10 µg/kg IV, Sedomidine, Audevard), with the addition of butorphanol (10-20 µg/kg IV, Torphadine, Dechra) when needed. A nose twitch was used when necessary. For horses racing or competing within 4 to 10 days following investigation, the procedures were achieved with a nose twitch only, without sedation because of drug testing considerations.