4/26 ATR 'Upper Airway Obstruction' Conversation

[Kasept]

For those that were interested in Tuesday's Horse Health Today segment with Dr. Allday, here is a July 2004 TTimes piece that beautifully differentiates throat obstructions and respective corrective measures:

http://www.thoroughbredtimes.com/hor...r-the-air.aspx

Veterinary Spotlight: Clear the air
Posted: Saturday, July 17, 2004

Careful diagnosis indicates type of treatment for wind problems

FORTY PERCENT of horses that perform poorly despite exhibiting no obvious physical problems have undiagnosed upper airway obstruction. The two most common types of wind problems are dorsal displacement of the soft palate, which causes flapping of loose tissue in the throat, and laryngeal hemiplegia, a paralysis of the arytenoid cartilage (flapper) usually on the left side of the horse's larynx.

Other less common problems are entrapment of the epiglottis, when the flap of cartilage that covers the opening of the larynx is sucked into the airway upon inhalation; epiglottic fold collapse, caused by weak epiglottic cartilage; and pharyngeal collapse, which occurs when suction from the horse inhaling causes the walls of the pharynx to collapse.

The soft palate is the tissue at the back of the roof of the mouth that separates the entrance of the esophagus from the entrance to the windpipe. Normally, it forms a tight seal that allows air into the windpipe and food into the esophagus, but not vice versa.

Dorsal displacement of the soft palate, or a flipped palate, occurs in certain horses that break this seal and begin breathing through the mouth and the nose at the same time, typically during peak exertion. The soft palate begins to flap, just as it does in humans who snore, and the flapping of this loose, soft tissue causes severe airway obstruction. The jockey will hear a gurgling or choking noise, and the horse will stop running until it swallows, which allows the soft palate to return to its proper position.

Three types of traditional surgery--myectomy, tenectomy, and staphylectomy-- routinely are performed on horses to stop them from flipping their palates.