Rationale for Lasering Soft Palates in Horses Put to the Test

Lasering the soft palate of horses for treating dorsal displacement of the soft palate (DDSP) causes scarring but does not "stiffen" the palate as hypothesized, reported Kira Alkabes, DVM, from the College of Veterinary Medicine at Purdue University.

DDSP is a common cause of respiratory noise and exercise intolerance in athletic horses. It results from an abnormal deviation of the palate (the roof of the mouth) in an upward direction that blocks the flow of air in the horse's nasal passages.

"Various procedures have been developed to treat DDSP in horses such as sternohyoideus and sternothyroideus myectomy, sternothyroideus tenectomy, staphlectomy, oral palatopharyngoplasty, epiglottic augmentation, largyngeal tie forward, and laser palatoplasty," explained Alkabes.

Laser palatoplasty is thought to cause scarring which will "stiffen" the soft palate. These stiffer palates are thought to be less likely to displace during exercise; however, little data is available supporting this theory.

To further explore whether laser palatoplasty does indeed create scarred and stiff palates, Alkabes and colleagues lasered the palates of six normal horses. Horses were then examined periodically between 0 and 45 days post-treatment.

Key findings of the study were that:

By Day 45, treated horses had significantly more scarring, swelling, and inflammation than control horses;

The muscle layers of the treated palates were injured. High-dose laser treatment caused more injury than low-dose treatments; and,

Palates of treated horses in the "high dose" group were significantly less stiff than control horses.

"As we suspected, soft palates were scarred and had less muscle after lasering but these palates were not stiffer. It is possible that the palates could become stiffer if horses were examined over a longer follow-up period," said Alkabes.

She added, "It is also important to remember that we used clinically normal horses in this study. More research using horses with DDSP is certainly warranted."

The study, "Evaluation of the effects of transendoscopic diode laser palatoplasty on clinical, histologic, magnetic resonance imaging, and biomechanical findings in horses" was published in the May 2010 edition of the American Journal of veterinary Research. Contributing authors were Jan Hawkins, DVM; Margaret Miller, DVM, PhD; Erin Nauman, PhD; William Wildmer, DVM, MS; Doug Dunco, MD; Jeffery Kras; Laurent Couetil, DVM, PhD; Timoth Lescun, BVSc; and, Raju Gautam.

This abstract is available on Pubmed.

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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