One of my theories about why Sheldon is so unhappy about bits is that, as a race horse, he most likely had his tongue tied during races.

Many trainers routinely tie down a horse’s tongue to prevent the Dorsal Displacement of the Soft Palate (DDSP) or to prevent a horse from getting its tongue over the bit. DDSP can interfere with the epiglottis and create breathing problems and that will slow a horse down.

How does that work?

Stacy Brown, a veterinary student, and Dr. Jeremy D. Hubert Assistant Professor of Equine Surgery address this topic in a paper from the Equine Health Studies Program at Louisiana State University’s School of Veterinary Medicine,

The epiglottis, a relatively rigid structure in the back of the throat, is positioned above the back edge of the soft palate, which is an extension of the hard palate (roof or mouth) and serves to separate the nasal and oral cavities. This anatomical arrangement helps assure that the air is directed into the trachea (windpipe).  However, during eating and swallowing, the soft palate moves upward as the epiglottis flips backward to cover the entry to the trachea.  This shift in the position of the epiglottis occurs so that food and saliva are directed into the esophagus and not into the trachea.  Dorsal displacement of the soft palate (DDSP) is a condition whereby the epiglottis becomes positioned above the soft palate (Figure 2).  Swallowing should replace the epiglottis to its normal position; however, if this does not occur then a tentative diagnosis of DDSP is provided.

DDSP may be intermittent (the most common) or persistent.  With intermittent displacement, the horse is able to replace the soft palate when swallowing.  When a horse is persistently displaced, the displacement is not corrected when the horse swallows. Because the displacement is not corrected with swallowing in horses with permanent DDSP, these horses are not capable of covering the opening of their trachea during eating, which may lead to coughing and ultimately aspiration pneumonia.

DDSP most commonly occurs in racehorses, but can occur in other types of performance horses, particularly those required to over flex at the poll (i.e. Hackney ponies and Saddlebreds). Owners and trainers often complain that these horses are “choking down” or are “gurgling”. These horses are often observed to be open-mouthed breathing during episodes of this loud, expiratory (while breathing out) gurgling noise.  Once the palate displaces they are unable to breathe sufficiently, which leads to rapid slowing or stopping, at which time, they usually swallow and replace the palate into normal position, causing the gurgling noise to dissipate and the open-mouth breathing to stop. Substantial exercise intolerance occurs during DDSP due to disruption in airflow.  The exercise intolerance and gurgling noise are due to the soft palate creating an expiratory airway obstruction because of its abnormal position. While gurgling is relatively common, DDSP cannot be ruled out in a horse that is exercise intolerant, but does not make a noise. Approximately 30% of horses affected with DDSP reportedly do not make a noise.

Tongue tying may make sense for race horses, but the practice can cause long-term tongue issues which can be tough to fix.

In Sheldon’s case, the issue with his tongue comes up (or out) when he’s got a bit in his mouth and he’s feeling stressed. If I’m schooling him in the field, his tongue mostly stays in his mouth; if he’s out on the trails or in a new situation, it comes right out.

With bitless bridle, his tongue stays put.

Recently Sheldon had some body work done and his jaw was obviously bothering him. During the work that was done on his bars, his tongue came out farther than any horse I’d ever seen!

What about you? Have you seen tongue issues like this with OTTBs?