Intermittent rostral displacement of the palatopharyngeal arch in a horse due to 4-BAD. [German]Original Title Intermittierende Rostralverlagerung des Arcus palatopharyngeus bei einem Pferd aufgrund einer Missbildung des vierten Kiemenbogens.

摘要

A 4 year old Holsteiner mare was presented to the Clinic for Horses of the University of Veterinary Medicine in Hannover for complaints of a respiratory noise occurring during exercise. A rostral displacement of the palatopharyngeal arch was diagnosed by the referring veterinarian in the sedated horse. The horse was examined clinically. An intermittent, inspiratory noise was heard during exercise. During endoscopy as well as during radiography a rostral displacement of the palatopharyngeal arch could be diagnosed only in a sedated condition or immediately after antagonising a sedation. During ultrasonography laryngeal malformation was evident as an abnormal space between the cricoid and thyroid cartilage. The cricoarytenoideus lateralis muscle appeared to be in an abnormal location. The articulation between the cricoid and thyroid cartilage was not obvious. Based on our experiences with this case, resting upper airway endoscopy should be performed routinely in the sedated and unsedated horse. An ultrasonographic examination of the larynx can help to confirm the diagnosis of a laryngeal malformation. Based on this report, exercise endoscopy alone cannot replace resting endoscopy in the sedated horse in every case. The rostral displacement of the palatopharyngeal arch could be identified as the potential cause of the respiratory noise in this horse by exercise endoscopy because stridor occurred during the endoscopically visible displacement.