The pharynx in horses is a muscular tube that serves as a passageway for both the respiratory and digestive systems. It connects the nasal and oral cavities to the larynx and esophagus, facilitating the movement of air to the lungs and food to the stomach. The equine pharynx plays a role in breathing, swallowing, and vocalization. Anatomically, it is divided into the nasopharynx, oropharynx, and laryngopharynx, each with distinct functions. This section provides access to peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and clinical relevance of the pharynx in equine health, including its involvement in respiratory and swallowing disorders.
Willoughby RA, MacDonald E, McSherry BJ, Brown G.Groups of young growing horses were fed toxic amounts of lead only, zinc only and the same amounts of lead and zinc together. Those fed Pb only developed pharyngeal and laryngeal paralysis ("roaring") whereas those fed Zn only and Pb and Zn together developed the same clinical syndrome which included swelling at the epiphyseal region of the long bones, stiffness and lameness. Anemia and decreased weight gains were most pronounced in animals fed Zn for the longest periods. Animals fed Pb only did not become anemic and weight loss did not occur until after there was an interference in swallowing...
Jones FS.The lower nasal mucosa and the pharynx of thirty eastern and twenty-three western horses have been examined for streptococci. Eight of the eastern horses carried non-hemolytic streptococci on the nasal mucosa. From the pharynx of six, non-hepiolytic streptococci were cultivated. The throats of eighteen contained strains of the hemolytic type. The nasal mucosa of the eastern horses failed to show hemolytic streptococci. Eight western horses carried non-hemolytic streptococci in the nasal passage; eight also harbored the hemolytic type. Twenty-two strains were isolated from the pharynx. Eleven w...
Knight AP.Dysphagia developed in a 2-year-old Quarter Horse filly following an incident in which it fell over backward while exercising on a mechanical horse walker. Hyperextension of the neck at this time apparently caused unilateral rupture of the longus capitis (rectus capitis ventralis major) and the rectus capitis ventralis minor muscles at their insertion. An existing mycotic lesion involving the dorsomedial wall of the left guttural pouch may have weakened the area of insertion of the involved muscles. Tearing of the tendinous insertion of these muscles caused damage to the IX, X, and XI cranial ...
Bilzer T, Grabner A, Stitz L.Tissues from nine horses and one donkey suffering from natural Borna disease were investigated. Clinically, all animals demonstrated progressive reduced mentation and aggravating gait disturbances. During the clinical course anorexia and progressive loss of proprioception were observed. Cranial nerve failure was accompanied by signs of pharyngeal paralysis, sialorrhea, bruxism, and by blindness. Virologically, infectious virus was detected in the brain of all animals investigated but was not found regularly in all areas of the brain. However, in all cases, infectivity was found in the thalamus...
Heffron CJ, Baker GJ.Fibreoptic endoscopy was used to study the movements of the larynx and pharynx during nasal occlusion in 10 horses, which showed signs consistent with functional pharyngeal obstruction (FPO) on exercise. Cine-endoscopic films were made on 3 such horses. Consideration of the anatomy of the region indicates that FPO may best be regarded as a subluxation of the nasopharyngeal and larygneal airways and it was found that a constant component of the movements which brought about this subluxation was a marked caudal retraction of the larynx. It is suggested that this caudal retraction of the larynx o...
Gehlen H, Ohnesorge B.To describe removal of guttural pouch chondroids through a laser fenestrated mesial septum in a pony with an obstructed pharyngeal ostium of the left guttural pouch. Methods: Case report. Methods: Pony. Methods: Transendoscopic laser neodymium:yttrium aluminum garnet (Nd:YAG) fenestration of the mesial guttural pouch septum was made by contact method (bare fiber, 15-25 W, exposure time 4 seconds). Dissected tissue was removed by transendoscopic monopolar electrosurgery (loop electrode, cutting blade) and multiple chondroids of varying size were removed from the left guttural pouch through the ...
Linford RL, O'Brien TR, Wheat JD, Meagher DM.A lateral radiograph of the pharyngeal region provides a technique for identifying pharyngeal disorders, including entrapment of the epiglottic cartilage and dorsal displacement of the soft palate. Epiglottic cartilage length, predicted from radiographs by measurement from the body of the thyroid cartilage to the tip of the epiglottis (thyroepiglottic length), was well correlated to actual length at postmortem examination (r2 = 0.98). Thyroepiglottic length, corrected for magnification, was 8.76 +/- 0.44 cm in 24 healthy Thoroughbreds. Nine Thoroughbreds with entrapment of the epiglottic carti...
Luedke LK, Cheetham J, Mohammed HO, Ducharme NG.To evaluate the efficacy of various treatments for dysphagia after laryngeal surgery. Methods: Retrospective. Methods: Horses treated for dysphagia after laryngeal surgery. Methods: Medical records of horses treated for dysphagia after prosthetic laryngoplasty (PLP) or partial arytenoidectomy (PA) were reviewed. Signalment, prior surgery, preoperative videoendoscopic diagnosis, and surgical treatments were recorded. Short- and long-term follow-up were obtained. Chi-square and logistical regression were performed to correlate independent variables and outcomes. Results: Forty-four percent of ho...
Church S, Wyn-Jones G, Parks AH, Ritchie HE.Seventeen cases of guttural pouch mycosis (including two bilaterally affected cases) were diagnosed in a three year period. The presenting signs were, in order of frequency, epistaxis at rest, nasal catarrh, pharyngeal paralysis, ipsilateral laryngeal hemiplegia, swelling of the submandibular/parotid region, extension of the head and neck and dyspnoea. Ligation of the origin of the internal carotid and occipital arteries was attempted in 10 of the cases exhibiting epistaxis. Bilateral ligation was performed on one animal with an untoward sequelae. Where surgery was successfully completed furth...
