Incidence of swallowing during exercise in horses with dorsal displacement of the soft palate
Version of Record online: 5 JUL 2010
© 2010 EVJ Ltd
Equine Veterinary Journal
Volume 42, Issue 8, pages 732–737, November 2010
How to Cite
PIGOTT, J. H., DUCHARME, N. G., MITCHELL, L. M., SODERHOLM, L. V. and CHEETHAM, J. (2010), Incidence of swallowing during exercise in horses with dorsal displacement of the soft palate. Equine Veterinary Journal, 42: 732–737. doi: 10.1111/j.2042-3306.2010.00116.x
- Issue online: 5 JUL 2010
- Version of Record online: 5 JUL 2010
- [Paper received for publication 30.10.09; Accepted 10.02.10]
- dorsal displacement;
Reasons for performing study: The relationship between dorsal displacement of the soft palate (DDSP) and swallowing is unclear.
Objective: To quantify the relationship between DDSP and swallowing in horses at exercise.
Hypotheses: The frequency of swallowing increases immediately prior to DDSP in horses at exercise.
Methods: Videoendoscopic and upper airway pressure data were collated from horses with a definitive diagnosis of DDSP at exercise. Horses with no upper airway abnormalities were matched by age, breed and sex and used as controls. Sixty-nine horses were identified with a definitive diagnosis of DDSP during the study interval. Airway pressure data were available for 42 horses.
Results: The majority of horses displaced at high exercising speeds while accelerating; a smaller number displaced during deceleration after peak speed had been reached. Horses swallowed significantly more frequently in the 1 min immediately preceding DDSP than in the control horses at equivalent speeds. DDSP at exercise results in a significant increase in tracheal expiratory pressure, a significant decrease in pharyngeal expiratory pressure and a significantly less negative pharyngeal inspiratory pressure compared to matched controls and compared to the pressures during the 1 min interval prior to DDSP. There was no significant difference between any measure of airway pressure before or after a swallow when examined at each time interval in the DDSP population.
Conclusions: The frequency of swallowing decreases with increasing speed in normal horses. In contrast, the frequency of swallowing increases immediately prior to onset of DDSP. This is not a result of pharyngeal and tracheal pressure changes.
Potential relevance: The increased frequency of swallowing observed prior to DDSP may be related to the aetiology of the disease.