Marion duPont Scott Equine Medical Center, 17690 Old Waterford Road, PO Box 1938, Leesburg, Virginia 20177, USA.
Ventriculocordectomy reduces respiratory noise in horses with laryngeal hemiplegia
Article first published online: 5 JAN 2010
2003 EVJ Ltd
Equine Veterinary Journal
Volume 35, Issue 6, pages 570–574, September 2003
How to Cite
BROWN, J. A., DERKSEN, F. J., STICK, J. A., HARTMANN, W. M. and ROBINSON, N. E. (2003), Ventriculocordectomy reduces respiratory noise in horses with laryngeal hemiplegia. Equine Veterinary Journal, 35: 570–574. doi: 10.2746/042516403775467135
- Issue published online: 5 JAN 2010
- Article first published online: 5 JAN 2010
- Paper received for publication 16.09.02; Accepted 28.02.03
- laryngeal hemiplegia;
- respiratory noise
Reasons for performing study: Show and performance horse with laryngeal hemiplegia (LH) often present for excessive respiratory noise ratherthan significant exercise intolerance. Therefore, the goal of surgery in these horses is to reduce re spiratory noise but there are no quantitative studies evaluating the effect of any upper-airway surgery in LH-affected horses.
Objective: To determine whether bilateral ventriculocordectomy (VC) reduces respiratory noise in exercising horses with laryngeal hemiplegia.
Methods: Six Standardbred horses with normal upperairways were used in this study. Respiratory sounds and inspiratory trans-upper airway pressure (Pui) were measured in all horses before and after induction of LH, and 30, 90 and 120 days after VC. In horses with LH, spectrogram analysis revealed 3 inspiratory sound formants centred at approximately 400, 1700 and 3700 Hz. Inspiratory sound levels (SL) and the sound intensity of the 3 inspiratory formants (F1, F2, F3 respectively) were measured using a computer-based sound analysis programme.
Results: In LH-affected horses, Pui, inspiratory SL and the sound intensity of F2 and F3 were significantly increased compared to baseline values. At 90 and 120 days afterVC the sound intensities of F2 and F3 returned to baseline values. The Pui and SL, were significantly decreased compared to LH values, but remained different from baseline.
Conclusions: VC effectively reduces inspiratory noise in LH-affected horses by 90 days following surgery. Inspiratory trans-upperairway pressures are improved 30 days following VC, but do not return to baseline values.
Potential relevance: VC can be recommended as a surgical treatment of LH-affected horses if reduction of respiratory noise is the primary objective of surgery. Further studies are required to determine if variations of the surgical technique used in this study will have similar results.