Effect of head and neck position on pharyngeal diameter in horses.
Abstract: Dynamic nasopharyngeal collapse with upper airway obstruction is an important cause of exercise intolerance in performance horses. Its underlying pathophysiology is not fully understood. We hypothesize that head position affects pharyngeal diameter, and thus head position may be a contributing factor to nasopharyngeal obstruction. Fifteen adult healthy horses were subjected to endoscopy and radiography at rest. The pharyngeal diameter was measured at nine different head and neck positions. The effect of sedation and breathing cycle on the pharyngeal diameter was determined, and the relationship between the head angle and the pharyngeal diameter was analyzed. There was a significant influence of head and neck position on pharyngeal diameter, with head position having the major effect (P < 0.001); neck position was less important, but still significant (P < 0.05). The smallest pharyngeal diameter was found at the dorsal, flexed position, which is a clinically important head position in dressage horses. The largest pharyngeal diameter was found at the extended midway position. At each head level, the pharyngeal diameter decreased with flexing the head and it increased with extending the head. The head angle was not associated with pharyngeal diameter, and neither sedation status nor breathing cycle significantly affected pharyngeal diameter. A decrease in pharyngeal diameter will limit the airflow through the upper respiratory tract, and it may result in turbulence with subsequent dynamic collapse. Head and neck position should therefore be considered a possible contributing factor in horses with suspected nasopharyngeal dysfunction.
Publication Date: 2010-10-27 PubMed ID: 20973380DOI: 10.1111/j.1740-8261.2010.01701.xGoogle Scholar: Lookup
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- Journal Article
Summary
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The research article discusses the influence of head and neck position on the pharyngeal diameter in horses, with findings suggesting that certain positions may contribute to nasopharyngeal obstruction, a leading cause of exercise intolerance in athletic horses.
Objective and Hypothesis
- The researchers aimed to understand the pathophysiology of dynamic nasopharyngeal collapse, a condition that affects the performance of horses during exercise. They hypothesized that the position of a horse’s head could affect the diameter of the pharynx and therefore potentially contribute to airway obstruction in these animals.
Methods
- 15 healthy adult horses were included in the study for examination. The researchers performed endoscopy and radiography on these horses at rest.
- The pharyngeal diameter was then measured at nine different head and neck positions.
- The team looked at the impact of sedation status and the breathing cycle on the pharyngeal diameter and analyzed the relationship between the head angle and the diameter of the pharynx.
Findings
- The results showed a significant correlation between head and neck position and pharyngeal diameter, with head position noted to exert a greater impact than neck position.
- The smallest pharyngeal diameter was found in the dorsal, flexed position—an essential position in the dressage style of horse training. The largest diameter was found to be at the extended midway position.
- Within each head level, the pharyngeal diameter was observed to decrease when the head was flexed and increase upon extension of the head.
- Interestingly, no significant associations were found between the head angle and the pharyngeal diameter nor between the sedation status and the breathing cycle and the diameter of the pharynx.
Implications
- The study suggests that a decreased pharyngeal diameter can restrict airflow through the upper respiratory tract, potentially causing turbulence and subsequent dynamic collapse. As such, the position of the horse’s head and neck should be considered a potential contributing factor in horses exhibiting signs of nasopharyngeal dysfunction.
Cite This Article
APA
Cehak A, Rohn K, Barton AK, Stadler P, Ohnesorge B.
(2010).
Effect of head and neck position on pharyngeal diameter in horses.
Vet Radiol Ultrasound, 51(5), 491-497.
https://doi.org/10.1111/j.1740-8261.2010.01701.x Publication
Researcher Affiliations
- Clinic for Horses, University of Veterinary Medicine, Hannover, Bünteweg 9, Germany. anja.cehak@tiho-hannover.de
MeSH Terms
- Animals
- Female
- Head / anatomy & histology
- Horse Diseases / diagnostic imaging
- Horse Diseases / physiopathology
- Horses
- Male
- Nasopharyngeal Diseases / diagnostic imaging
- Nasopharyngeal Diseases / etiology
- Nasopharyngeal Diseases / physiopathology
- Nasopharyngeal Diseases / veterinary
- Nasopharynx / anatomy & histology
- Nasopharynx / diagnostic imaging
- Nasopharynx / physiopathology
- Neck / anatomy & histology
- Orchiectomy
- Pharynx / anatomy & histology
- Pharynx / diagnostic imaging
- Posture
- Radiography
Citations
This article has been cited 11 times.- Phelipon R, Lansade L, Razzaq M. Using deep learning models to decode emotional states in horses. Sci Rep 2025 Apr 23;15(1):13154.
- König von Borstel U, Kienapfel K, McLean A, Wilkins C, McGreevy P. Hyperflexing the horse's neck: a systematic review and meta-analysis. Sci Rep 2024 Oct 2;14(1):22886.
- Bogossian PM, Pereira JS, da Silva NF, Hilgert AR, Seidel SRT, Fülber J, Belli CB, Fernandes WR. Social facilitation of trotting: Can horses perceive and adapt to the movement of another horse?. PLoS One 2024;19(8):e0309474.
- Scholler D, Wittenberg J, Zablotski Y, May A. Do tight nosebands have an effect on the upper airways of horses?. Vet Med Sci 2024 Jul;10(4):e1478.
- Tilley P, Simões J, Sales Luis JP. Effects of a 15° Variation in Poll Flexion during Riding on the Respiratory Systems and Behaviour of High-Level Dressage and Show-Jumping Horses. Animals (Basel) 2023 May 22;13(10).
- Noh D, Choi S, Choi H, Lee Y, Lee K. Dynamic computed tomography evaluation of the nasopharynx in normal Beagle dogs. J Vet Med Sci 2021 Sep 3;83(9):1356-1362.
- Veen I, Killian D, Vlaminck L, Vernooij JCM, Back W. The use of a rein tension device to compare different training methods for neck flexion in base-level trained Warmblood horses at the walk. Equine Vet J 2018 Nov;50(6):825-830.
- Mellor DJ, Beausoleil NJ. Equine Welfare during Exercise: An Evaluation of Breathing, Breathlessness and Bridles. Animals (Basel) 2017 May 26;7(6).
- Rubin JA, Holt DE, Reetz JA, Clarke DL. Signalment, clinical presentation, concurrent diseases, and diagnostic findings in 28 dogs with dynamic pharyngeal collapse (2008-2013). J Vet Intern Med 2015 May-Jun;29(3):815-21.
- Go LM, Barton AK, Ohnesorge B. Objective classification of different head and neck positions and their influence on the radiographic pharyngeal diameter in sport horses. BMC Vet Res 2014 May 23;10:118.
- Go LM, Barton AK, Ohnesorge B. Pharyngeal diameter in various head and neck positions during exercise in sport horses. BMC Vet Res 2014 May 23;10:117.
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