Equis ISSN 2398-2977

Guttural pouch: mycosis

Contributor(s): Safia Barakzai, Tim Brazil, Christopher Brown, John P Caron, Graham Munroe, Prof Jonathon Naylor, Jamie Prutton


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  • Aspergillus spp Aspergillus spp - probably opportunist invader.
  • The precise cause is unknown, but an underlying lesion of the arterial wall such as an aneurysmal dilatation has been suggested as a predisposing factor.


  • Inhaled Aspergillus nidulans spores → colonize wall of arterial vessel in the guttural pouch (for normal anatomy see Guttural pouch: normal 03 - endoscopy).
  • Growth of mycotic plaque and erosion of arterial wall → spontaneous hemorrhage → epistaxis or catastrophic hemorrhage → death.
  • More rarely, mycotic plaque impinges major nerves, eg vagus (sympathetic trunk), glossopharyngeal, hypoglossal, facial nerve → Horner's syndrome Neurology: Horner's syndrome, pharyngeal paralysis and facial paralysis Facial nerve: trauma.
  • Mycotic plaque is variable in size and composed of necrotic tissue, cell debris, bacteria and fungal mycelia. Usually brown, yellow, black or white attached to wall of pouch. The majority are in the medial part of the pouch on the dorsal caudal aspect medial to the temporohyoid articulation. Occasional lesions are more lateral and in the ventrolateral part of the pouch Guttural pouch: mycosis 02 - pathology.


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Coleman M C & Hardy J (2019) Suspected retropharyngeal haemorrhage as a complication of guttural pouch mycosis. Equine Vet Ed 31 (2), 71-74 VetMedResource.
  • Watkins A R & Parente E J (2018) Salpingopharyngeal fistula as a treatment for guttural pouch mycosis in seven horses. Equine Vet J 50 (6), 781-786 PubMed.
  • Chidlow H B & Slovis N M (2017) Guttural pouch mycosis in two foals. Equine Vet Ed 29 (4), 213-218 VetMedResource.
  • Bonilla A G, Scansen B A, Hurcombe S D & Mudge M C (2015) Potential for iatrogenic coil embolization of the caudal cerebellar artery during treatment of internal carotid artery bifurcation in two horses with guttural pouch mycosis. JAVMA 247 (12),1427-1432 PubMed.
  • Cousty M, Tricaud C, De Beauregard T et al (2015) Ligation of the ipsilateral common carotid artery and topical treatment for the prevention of epistaxis from guttural pouch mycosis in horses. Vet Rec 178 (2), 44 PubMed
  • Kampmann C, Thiede S & Kuhn M (2014) Transarterial coil embolization of the internal carotid artery and the maxillar artery in a standing horse for therapy of guttural pouch mycosis. Pferdeheilkunde 30 (2), 183-187 VetMedResource.
  • Eichentopf A, Snyder A, Recknagel S, Uhlig A, Waltl V & Schusser G F (2013) Dysphagia caused by focal guttural pouch mycosis: mononeuropathy of the pharyngeal ramus of the vagal nerve in a 20-year-old pony mare. Ir Vet J 66 (1) 13 PubMed.
  • Dobesova O, Schwarz B, Velde K et al (2012) Guttural pouch mycosis in horses: retrospective study of 28 cases. Vet Rec 171 (22), 561 PubMed.
  • Jones A, Davison K & Coomer R (2010) Investigation and management of epistaxis secondary to guttural pouch mycosis in a horse. UK Vet 15 (7), 10-18 VetMedResource.
  • Hahn C (2008) Common peripheral nerve disorders in the horse. In Pract 30 (6), 328-329 VetMedResource.
  • Archer D (2008) Differential diagnosis of epistaxis in the horse. In Pract 30 (1), 20-29 VetMedResource.
  • Pollock P J (2007) Diagnosis and management of guttural pouch mycosis. Equine Vet Educ 19 (10), 522-527 VetMedResource.
  • Lepage O M & Piccot-Crézollet (2005) Transarterial coil embolisation in 31 horses (1999-2002) with guttural pouch mycosis: a 2-year follow-up. Equine Vet J 37 (5), 430-434 PubMed.
  • Lepage O M, Perron M F & Cadore J L (2004) The mystery of fungal infection in the guttural pouches. Vet J 168 (1), 60-64 PubMed.
  • Leveille R, Hardy J et al (2000) Transarterial coil embolization of the internal and external carotid and maxillary arteries for prevention of hemorrhage from guttural pouch mycosis in horses. Vet Surg 29 (5), 389-397 PubMed.
  • Speirs V C et al (1995) Is specific antifungal therapy necessary for the treatment of guttural pouch mycosis in horses? Equine Vet J 27 (2), 151-152 PubMed.
  • Davis E W et al (1994) Successful treatment of guttural pouch mycosis with itraconazole and topical enilconazole in a horse. J Vet Intern Med (4), 304-305 PubMed.
  • Lane J G (1989) The management of the guttural pouch mycosis. Equine Vet J 21 (5), 321-324 PubMed.
  • Greet T R (1987) Outcome of treatment in 35 cases of guttural pouch mycosis. Equine Vet J 19(5), 483-487 PubMed.