Exercise’s Effects on Respiratory Pathogen Detection in Healthy Horses - EquiManagement on Audio

0:00All the articles you have come to love in Equamanagement Magazine are now available on the Equamanagement on Audio podcast. Each article is released as its own separate episode to make them quick and easy to listen to. Just search Equamanagement on Audio on your favorite podcast player to listen to all the latest articles. Exercises effects on respiratory pathogen detection and healthy horses. At the 2025 American Association of Equine Practitioners Convention, Dr. Nicola Pusterella, Professor of Equine Internal Medicine at the University of California Davis School of Veterinary Medicine, presented his research on the role of exercise in detecting selected respiratory pathogens. He began by reminding practitioners that stress, transport, co-mingling with cons specifics, lack of bio-security, age of the horse, vaccination status, and use can predispose horses to infection.

1:00We can all realize that putting an ill horse beside a healthy horse is high risk. He added, what we don't know is how this relates to subclinical shutters. The overall rate of subclinical shutters is highly variable, depending on the respiratory pathogen, population, and use of the horses, as well as season. Pusterella and colleagues conducted a study investigating the role of exercise in detecting selected respiratory pathogens, using nose wipes collected from healthy performance horses before and after exercise, when nasal secretions were increased. This was a voluntary study that trainers elected to enroll their healthy horses in, at various racing and training locations in spring 2024. Nose wipes were chosen over more invasive nasal swabs. All nasal wipes were processed for nucleic acid purification and tested for true pathogens. Aquine Herpes virus 1 and 4, Streptococcus equisub species equi.

2:03Pencils, EHV2 and 5, S-equisub species zoepidemicus and an endogenous control. We compared the frequencies and quantitation for each pathogen in pre and post-exercise samples, said Pusterella. We weren't really expecting too much because the samples were collected voluntarily from healthy horses. But surprisingly, quite a fair number of racing horses had a significant increase in EHV1 N equals 13 in the post-exercise samples. A similar increase in post-exercise frequency of detection was observed for EHV2 5 and S-equisub species zoepidemicus. We didn't know what to do with this information because the horses were not clinically affected, said Pusterella. They did determine that collecting samples via nasal wipes is easier, less invasive, and better tolerated by horses than swabs.

3:03Commensal pathogens are ideal to study dynamic rates of shedding in various horse populations. Pathogen frequency varied by horse population, that is racing versus showing. Specifically, racing horses had higher rates of EHV1, 2 and 5, and S-equisub species zoepidemicus than show horses. Exercise increased frequency of pathogen detection in nasal wipes. Absolute quantitation of pathogens reduced with exercise.