The guttural pouch is a unique anatomical structure in horses, consisting of a pair of air-filled sacs located within the head. These sacs are extensions of the Eustachian tubes and are situated between the base of the skull and the atlas vertebra. The guttural pouch is involved in various physiological functions, including temperature regulation of blood traveling to the brain and possibly influencing auditory processes. Due to its location, the guttural pouch is susceptible to infections and diseases such as guttural pouch mycosis and empyema, which can have significant health implications for horses. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, function, and clinical aspects of the guttural pouch in equine health.
Babptiste KE, Holladay SD, Freeman LE.An improved technique for preparing casts of the equine guttural pouch is described. The new technique is simplified and inexpensive in comparison to previous techniques and produces highly accurate anatomic models which are both durable and flexible. Methods: Silicone rubber bathtub caulk was injected into the guttural pouches of horse cadavers. The silicone was allowed to cure overnight, and casts were removed by dissection. The new technique was then used to evaluate changes in the shape of the guttural pouch with changes in head position. Results: With flexion of the atlanto-occipital join...
Tate LP, Blikslager AT, Little ED.Guttural pouch tympanites was diagnosed in eight foals with respiratory stridor and tympanic swelling in the parotid region. Three foals were treated by transendoscopic neodymium:yttrium aluminum garnet (Nd:YAG) laser fenestration of the median septum between the guttural pouches. One foal died of pneumonia, and the other two foals recovered completely, although the fenestration later closed in one foal. Five foals were treated by creating a salpingopharyngeal fistula using transendoscopic laser irradiation; complete resolution of the tympanites occurred. Transendoscopic laser surgery in stand...
Freeman DE, Donawick WJ, Klein LV.The effect of a single ligature on back pressure in the internal carotid artery was studied in nine horses. In six anesthetized horses, one internal carotid artery was catheterized 2 cm from its origin and blood pressure was recorded continuously. Then the artery was ligated, pressure was recorded again, and the horses were euthanatized. In another three anesthetized horses, indwelling catheters were placed in both internal carotid arteries and a loose ligature was placed proximal to one catheter. After horses recovered from anesthesia, the ligature was tied and blood pressure was recorded in ...
Baptiste KE, Cake MH.The guttural pouch is a large, air-filled diverticulum of the auditory tube, present in the horse and other species. Lipid analysis of saline lavage from the equine guttural pouch has demonstrated the presence of phospholipids and neutral lipids in amounts that are variable but consistently greater than in any other species described. A stain specific for choline-containing phospholipids has demonstrated the presence of phospholipid-containing vesicles only within the cells of subepithelial, seromucoidlike glands, suggesting that these cells incorporate phospholipids in their secretions. The f...
van Nieuwstadt RA, Kalsbeek HC.In a horse with chronic unilateral nasal discharge guttural pouch mycosis caused by Aspergillus fumigatus was diagnosed. A percutaneous indwelling catheter was surgically installed in the left guttural pouch. Initial treatment with a povidone iodine solution proved to be unsatisfactory. Treatment was continued by administering enilconazole by ways of an indwelling through-the-nose-catheter. The latter treatment resulted in complete recovery.
Sweeney CR, Freeman DE, Sweeney RW, Rubin JL, Maxson AD.Three horses were determined to have hemorrhage into a guttural pouch unassociated with mycosis, empyema, neoplasia, or foreign body. The source of the hemorrhage appeared to be the rupture of the longus capitis muscle and its associated vascular supply.
Govan JR, Sarasola P, Taylor DJ, Tatnell PJ, Russell NJ, Gacesa P.The isolation and characterization of a mucoid, alginate-producing strain of Pseudomonas aeruginosa from a nonhuman host, namely, in chondroids from an equine guttural pouch, is reported for the first time. Pure cultures of P. aeruginosa 12534 were isolated from a 17-month-old pony mare with a history of chronic bilateral mucopurulent nasal discharge from the right guttural pouch. Transmission electron microscopy of chondroids showed mucoid P. aeruginosa growing as microcolonies within a matrix of extracellular material. On the basis of expression of the mucoid phenotype under different growth...
Sullins KE.Common equine upper respiratory conditions are diagnosed via endoscopy. Endoscopic surgery facilitates correction of many conditions without general anesthesia or laryngotomy, reducing the morbidity and cost of the procedures. Modalities of endoscopic surgery include the Nd-YAG laser or electrosurgery, which may be complementary. The least expensive method is electrosurgery, and instruments are available that can be passed through the biopsy channel of the endoscope. Conditions amenable to such procedures include entrapped epiglottis, rostral displacement of the palatopharyngeal arch, pharynge...
Seahorn TL, Schumacher J.Chondroid masses were successfully removed from the guttural pouches of 2 horses, using an endoscope, a snare, and a vacuum pump. This technique is an alternative to surgical removal of chondroid masses in patients when basic lavage of the affected guttural pouch is ineffective. Complications were not encountered. Advantages of this snare technique include avoidance of surgery and its potential complications, minimal recovery time, and minimal expense.
Embertson RM.Upper respiratory tract conditions of the older horse that are not necessarily associated with athletic exercise intolerance are discussed. Some of the diseases described include ethmoid hematoma, sinus disease, guttural pouch empyema and mycosis, retropharyngeal abscess, nasopharyngeal cicatrix, arytenoid chondropathy, and neoplasia.
Sweeney RW, Hansen TO.Six horses with dysphagia (attributable to botulism, glossitis, or guttural pouch mycosis) were given a commercially available liquid diet as the sole source of nutrition. Seven horses with hypophagia caused by severe bacterial pleuropneumonia or peritonitis were given the liquid diet to supplement food consumed voluntarily. The liquid diet was administered through a nasogastric tube 2 or 3 times daily. Body weight did not change significantly, and pertinent laboratory values remained at satisfactory concentrations throughout the feeding period. Serious complications were not encountered. Thre...
Pirie M, Pirie HM, Wright NG.The surface features of the upper respiratory tract of 20 clinically normal horses of various ages and types were studied with scanning electron microscopy. In the rostral part of the nasal cavity, there was a wide zone of non-ciliated epithelium whereas, caudally, the surface was well ciliated. This latter type of epithelium extended into the nasopharynx and guttural pouches although scattered areas of non-ciliated microvillous cells were also found.
Hardy J, Robertson JT, Wilkie DA.Ischemic optic neuropathy accompanied by blindness was induced in 2 horses after surgical occlusion of the external and internal carotid and greater palatine arteries, performed as part of the management of guttural pouch mycosis. The blindness was acute and unilateral and may have been caused by ischemic retinal damage. Vascular occlusion is a recommended procedure for treatment of guttural pouch mycosis. Retinal damage and blindness are a possible complication if all possible sources of hemorrhage are occluded.
McCue PM, Freeman DE, Donawick WJ.From 1977 to 1986, guttural pouch tympany was diagnosed in 15 horses--11 fillies and 4 colts. Review of the medical records provided results of physical, microbiologic, radiographic, and endoscopic examinations, treatment protocols, complications, and recovery rate. All affected horses had visible swelling in the parotid gland region, 9 had abnormal respiratory noise, 5 had pneumonia, and 1 had dysphagia. Six horses were treated by median septum fenestration alone, and in 8 horses, this procedure was combined with resection of the mucosal flap at the pharyngeal orifice of the eustachian tube. ...
Freeman DE, Ross MW, Donawick WJ, Hamir AN.Balloon-tipped catheters were used to occlude the external carotid artery and its branches in nine horses with hemorrhage caused by guttural pouch mycosis. The internal carotid artery on the affected side was occluded simultaneously in four horses and had been occluded previously in two others. In three horses, a single balloon-tipped catheter was inserted in the external carotid artery beneath the floor of the guttural pouch and its tip was advanced blindly into distal branches. In one horse, the superficial temporal artery was occluded briefly during surgery by a balloon-tipped catheter so a...
Sweeney CR, Whitlock RH, Meirs DA, Whitehead SC, Barningham SO.Complications associated with Streptococcus equi infection developed in 15 (20.3%) of 74 horses on one farm included death, guttural pouch empyema, purpura hemorrhagica, upper respiratory tract obstruction, pneumonia, pleuropneumonia, agalactia, mesenteric lymph node abscessation, and periorbital abscessation. Death was attributed to pneumonia in 3 horses and to upper respiratory tract obstruction in 2 horses. One horse was euthanatized because of severe purpura hemorrhagica.
Greet TR.This paper describes the outcome of treatment of 30 cases of guttural pouch mycosis by ligation of the internal carotid artery on the cardiac side of the lesion and lavage of the affected pouch with natamycin. Twenty-three horses recovered fully following this treatment while laryngeal hemiplegia persisted in one case and slight dysphagia caused by pharyngeal hemiplegia in another. The remaining five horses died or were destroyed. Five horses with guttural pouch mycosis, which had shown no epistaxis but had pharyngeal hemiplegia, were treated by topical natamycin alone. Only two of these survi...
Caron JP, Fretz PB, Bailey JV, Barber SM, Hurtig MB.Epistaxis, caused by guttural pouch mycosis, was treated by balloon-tipped catheter and ligature occlusion of the involved arteries in 13 horses. In 7 horses, more than one artery was catheterized. Serious postoperative hemorrhage was prevented in all horses. Long-term endoscopic follow-up examination was possible in 8 horses, and all had complete regression of the fungal lesion as early as 5 weeks after surgery. Six of the 8 horses did not receive medical treatment. Problems related to the use of the balloon-tipped catheter technique were rare. There were incisional infections in 3 horses, ca...
Schumacher J, Hanselka DV.Nasopharyngeal cicatrices were observed endoscopically in 47 horses examined because of abnormal respiratory noises and/or exercise intolerance. A review of these cases revealed a correlation between cicatrization and age, sex, and the presence of other upper airway abnormalities. The age of affected horses ranged from 6 to 21 years, with a mean age of 12.7 +/- 7.8 (+/- 2 SD) years. Females were affected 2.7 times more frequently than males. Abnormalities commonly observed with a nasopharyngeal cicatrix included chondritis of the arytenoid cartilage, epiglottic deformity, and deformity of the ...
Grabner A.Mycosis of the guttural pouches is a sporadic disease characterized by diphtheroid-necrotizing inflammation, and is caused by different fungal species, mainly by Aspergillus spp., Penicillium spp. and Candida spp. Highest incidence is during summer in stable horses. Proper diagnosis often requires--besides detection by mycological techniques--histological examination of tissue obtained by bioptic endoscopy. Prognosis is hopeless in late stages of the infection because of the erosion of the carotid artery or accompanied by the fatal complications of a not reparable cranial nerve damage also in ...
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...
Greene HJ, O'Connor JP.A 16-year old thoroughbred mare was presented with dysphagia and food being ejected from the mouth and nostrils. Clinical signs were exhibited for three weeks before it was euthanased on humanitarian grounds. Post mortem examination revealed a soft haemangioma measuring 7 cm X 5 cm suspended from the roof of the medial compartment of the left guttural pouch.
Blazyczek I, Hamann H, Ohnesorge B, Deegen E, Distl O.The objective of the present study was to analyse the importance of the influences of sex, inbreeding coefficient, proportion of genes of the original breeds and the additive genetic contribution to the occurrence of guttural pouch tympany in foals belonging to German Warmblood breeds. Foals affected by guttural pouch tympany were ascertained in the Clinic of Horses, School of Veterinary Medicine Hannover. This data set comprised 22 German Warmblood foals with guttural pouch tympany, which were patients of the Clinic for Horses between 1994 and 2001. Information on the pedigrees and all availa...
Ernst NS, Freeman DE, Mackay RJ.A 6-year-old Appaloosa mare was examined because of inappetance, difficulty eating, and swelling and mucopurulent discharge in the right eye. Results: Results of a CBC and serum bio-chemical analysis revealed no important findings. Ophthalmologic examination revealed scarring and ulceration of the superficial layers of the cornea. Endoscopic examination of the upper portion of the respiratory tract and auditory tube diverticula (guttural pouches) revealed abnormal thickness of the right stylohyoid bone and a plaque suggestive of mycotic growth on the left internal carotid artery. Radiographic ...
Sasaki M, Hayashi Y, Koie H, Yamaya Y, Kimura J, Manglai D, Kawashima S, Endo H, Yamamoto M.The domestic horse (Equus caballus) have the large symmetrical guttural pouches (the auditory tube diverticulum) formed by saccate bulge of the auditory tube. In this study, CT examination was carried out in the head of Przewalski's horse (Equus przewalskii), the only true wild horse living at present. As results of the examination, Przewalski's horse possessed the large symmetrical guttural pouches divided into medial and lateral compartments by the stylohyoid bone. Moreover, the right and left guttural pouches meet each other at the median part to form a thin septum. As CT sections get close...
Blazyczek I, Hamann H, Ohnesorge B, Deegen E, Distl O.The objective of the present study was to analyse the importance of the influences of the sex, inbreeding coefficient and the additive genetic contribution to the occurrence of guttural pouch tympany in Arabian foals. Horses affected by guttural pouch tympany were ascertained in the Clinic for Horses, School of Veterinary Medicine Hannover. The data comprised 27 Arabian purebred foals with guttural pouch tympany. Of these 27 animals 22 were patients of the Clinic for Horses between 1994 and 2001 and 5 Arabian foals were sampled on the studs. Information on the pedigrees of these patients allow...
Koch DW, Easley JT, Nelson BB, Delcambre JJ, McCready EG, Hackett ES.Auditory tube diverticula, also known as guttural pouches, are naturally occurring dilations of the auditory tube in horses that communicate with the nasopharynx through a small ostium. Infection and select other conditions can result in inflammation and narrowing of the nasopharyngeal ostium, which prevents drainage of fluid or egress of air and can lead to persistent infection or guttural pouch tympany. Auditory tube diverticulotomy allows continuous egress from the auditory tube diverticula and is a feature of disease treatment in horses, in which medical treatment alone is not successful. ...
McLean R, Rash NL, Robinson C, Waller AS, Paillot R.Streptococcus equi subspecies equi (S. equi) is the causative agent of strangles, a highly contagious upper respiratory disease of equids. Streptococcus equi produces superantigens (sAgs), which are thought to contribute to strangles pathogenicity through non-specific T-cell activation and pro-inflammatory response. Streptococcus equi infection induces abscesses in the lymph nodes of the head and neck. In some individuals, some abscess material remains into the guttural pouch and inspissates over time to form chondroids which can harbour live S. equi. The aim of this study was to determine...
Barton AK, Cehak A, Rohn K, Ohnesorge B.To determine outcome after transendoscopic laser fenestration of the median septum and removal of the salpingopharyngeal fold of the guttural pouch on nasopharyngeal obstruction caused by poll flexion in Warmblood horses. Methods: Clinical study. Methods: Horses (n = 9). Methods: Nine horses with a history of performance insufficiency and respiratory noise during poll flexion were examined. On endoscopy, an often asymmetric dorsoventral obstruction of the nasopharynx occurred during poll flexion. Left lateral radiographs were taken in neutral, extended, and flexed head positions showed that me...
McCue PM, Freeman DE, Donawick WJ.From 1977 to 1986, guttural pouch tympany was diagnosed in 15 horses--11 fillies and 4 colts. Review of the medical records provided results of physical, microbiologic, radiographic, and endoscopic examinations, treatment protocols, complications, and recovery rate. All affected horses had visible swelling in the parotid gland region, 9 had abnormal respiratory noise, 5 had pneumonia, and 1 had dysphagia. Six horses were treated by median septum fenestration alone, and in 8 horses, this procedure was combined with resection of the mucosal flap at the pharyngeal orifice of the eustachian tube. ...
Freeman DE, Ross MW, Donawick WJ, Hamir AN.Balloon-tipped catheters were used to occlude the external carotid artery and its branches in nine horses with hemorrhage caused by guttural pouch mycosis. The internal carotid artery on the affected side was occluded simultaneously in four horses and had been occluded previously in two others. In three horses, a single balloon-tipped catheter was inserted in the external carotid artery beneath the floor of the guttural pouch and its tip was advanced blindly into distal branches. In one horse, the superficial temporal artery was occluded briefly during surgery by a balloon-tipped catheter so a...
Babptiste KE, Holladay SD, Freeman LE.An improved technique for preparing casts of the equine guttural pouch is described. The new technique is simplified and inexpensive in comparison to previous techniques and produces highly accurate anatomic models which are both durable and flexible. Methods: Silicone rubber bathtub caulk was injected into the guttural pouches of horse cadavers. The silicone was allowed to cure overnight, and casts were removed by dissection. The new technique was then used to evaluate changes in the shape of the guttural pouch with changes in head position. Results: With flexion of the atlanto-occipital join...
Rawlinson RJ, Jones RT.The history and clinical findings of 1 horses with guttural pouch mycosis referred to us are described. The salient features of the history and clinical signs common to both cases were profuse spontaneous nasal haemorrhage, partial pharyngeal paralysis; subsequently bilateral nasal discharge containing food material, inability to drink and parotid pain became evident. One case made a gradual recovery with conservative medical treatment while the second case was destroyed and submitted for post-mortem, histopathological and microbiological examination. This examination failed to establish the i...
Schaaf KL, Kannegieter NJ, Lovell DK.A Warmblood horse presented with a purulent nasal discharge that had failed to respond to antibiotic therapy. Radiography and endoscopy confirmed a large number of chondroid masses (over 200) in the left guttural pouch. Despite the large number of chondroids present, there was no external swelling evident. The masses were surgically removed via a hyovertebrotomy approach that provided excellent exposure, and no postoperative complications were encountered. Long term follow-up (3 years) confirmed a successful outcome.
Sweeney RW, Hansen TO.Six horses with dysphagia (attributable to botulism, glossitis, or guttural pouch mycosis) were given a commercially available liquid diet as the sole source of nutrition. Seven horses with hypophagia caused by severe bacterial pleuropneumonia or peritonitis were given the liquid diet to supplement food consumed voluntarily. The liquid diet was administered through a nasogastric tube 2 or 3 times daily. Body weight did not change significantly, and pertinent laboratory values remained at satisfactory concentrations throughout the feeding period. Serious complications were not encountered. Thre...
Zetterström SM, Matz BM, Neto RLALT, Lindley SES, Cole RC, Wilhite R, Boone LH.To describe the surgical findings, histopathological features, and long-term outcome for a horse with parotid salivary carcinoma. Methods: Case report ANIMALS: Twelve year old American Quarter Horse gelding. Methods: The gelding was presented for a 10 × 10 cm swelling below the base of the right ear. Ultrasonographic examination revealed a mass involving the right parotid salivary gland. Incisional biopsy was consistent with parotid carcinoma. The tumor was marginally excised. The lateral wall of the guttural pouch was excised with the mass and was reconstructed with a porcine small int...
Guillot J, Sarfati J, Ribot X, Jensen HE, Latgé JP.To detect antibodies against Aspergillus fumigatus antigens in serum samples from horses and to evaluate the relevance of this method as an alternative approach to the diagnosis of mycosis of the auditory tube diverticulum (guttural pouch mycosis [GPM]). Methods: Twelve clinically normal horses (controls) and 12 horses with GPM diagnosed by endoscopic observation of characteristic mycotic plaques. Methods: Antibodies to A fumigatus antigens were detected in serum by use of an ELISA and immunoblot analysis with extracellular antigens. Results: Antibodies against A fumigatus antigens were found ...
Krogh HV, Lundegaard HC.A case of guttural pouch mycosis in an 11-year-old horse is described. The fungus isolated was identified as Emericella nidulans. Housing under bad hygienic conditions without ventilation for three years might have been a predisposing factor.
Guillot J, Collobert C, Gueho E, Mialot M, Lagarde E.A case is reported in a 9-year-old Anglo-Arab horse with guttural pouch mycosis caused by Emericella nidulans. Acute death occurred by exsanguination following erosion of the external carotid artery. Histopathological examination of the mycotic plaque demonstrated septate hyphae, conidial heads, hülle cells and mature cleistothecia containing characteristic ascospores. Specific identification was confirmed by culture. In accordance with previous reports, Emericella nidulans should be considered as the major agent of guttural pouch mycosis in Equidae.
Deegen E.With the aid of a flexible glassfibre endoscope, a 300 W cold light source and a special adapted camera, colour photographs of the upper respiratory tract of horses were taken. These pictures served to present especially the disease processes of the different areas of the upper respiratory tract which lead to a constriction of the lumen. These included proliferation in the nose, guttural pouch diseases and larynx diseases such as hemiplegia, subepiglottic cysts, epiglottic entrapment and rostral displacement of the plica palatopharyngica. Furthermore endoscopic findings of changes in the soft ...
Sparks HD, Stick JA, Brakenhoff JE, Cramp PA, Spirito MA.3 foals were referred for treatment of tympany of the auditory tube diverticulum (guttural pouch). Results: Bilateral guttural pouch tympany was diagnosed in all 3 foals on the basis of clinical signs and results of radiographic and endoscopic evaluations and gutturocentesis. In each foal, previous medical or surgical interventions or both had failed to correct the problem. Results: Bilateral surgical resection of the plica salpingopharyngeus was performed. Follow-up telephone interviews with owners 8 months to 3 years after surgery revealed that long-term resolution of the tympany had been ac...
