Transcutaneous Ultrasonography Is a Feasible Method for Characterizing the Cricoarytenoideus Dorsalis Muscle in Horses.
Authors: Satoh Masato, Higuchi Tohru, Inoue Satoshi, Miyakoshi Daisuke, Gotoh Tadahiro
Journal: Journal of equine veterinary science
Summary
# Editorial Summary The cricoarytenoideus dorsalis muscle is the sole abductor of the equine larynx and therefore critical to maintaining airway patency, yet its clinical assessment has been restricted to advanced imaging modalities like transesophageal ultrasound, CT, and MRI—technologies unavailable in most equine practices. Satoh and colleagues validated a practical transcutaneous ultrasonographic technique in twenty live horses, which involved gentle contralateral manipulation of the larynx to facilitate visualisation of the muscle on the opposite side. Successfully imaging the CAD via this straightforward external approach opens significant diagnostic potential for evaluating recurrent laryngeal neuropathy (RLN), a costly performance-limiting condition affecting many horses, since ultrasonographic evidence of muscle atrophy or denervation changes could provide objective confirmation of the condition. Given that RLN diagnosis currently relies on endoscopic observation of laryngeal asymmetry and clinical signs, a non-invasive ultrasound method accessible in field and clinic settings could substantially improve early detection and inform prognosis and treatment decisions. This technique warrants integration into standard laryngeal examination protocols and further investigation regarding its sensitivity and specificity for detecting RLN-related pathology.
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Practical Takeaways
- •You can now assess the CAD muscle using standard ultrasound equipment at the clinic or barn without requiring referral for advanced imaging
- •The technique is simple: displace the larynx laterally with one hand while scanning transcutaneously with the other—practice on normal horses first
- •This method could support earlier or more frequent monitoring of horses at risk for or recovering from laryngeal neuropathy, potentially improving outcomes
Key Findings
- •Transcutaneous ultrasonography successfully imaged the cricoarytenoideus dorsalis muscle in all 20 live horses using an external approach
- •Laryngeal displacement via manual pressure from the opposite side improved visualization of the CAD muscle
- •This non-invasive technique may provide a practical alternative to transesophageal ultrasound, CT, or MRI for CAD assessment