Equis ISSN 2398-2977

Esophagus: obstruction

Synonym(s): Choke

Contributor(s): Roberta Baxter, Mark Hillyer, Prof Jonathon Naylor, Kate Hepworth-Warren

Introduction

  • Esophageal obstruction is a relatively common cause of acute dysphagia and discomfort in the horse.
  • Colloquially known as 'choke'.
  • Cause: ingestion of material that when swallowed, becomes impacted in the esophagus and does not pass into the stomach.
  • Signs: passage of ingesta and saliva down the nostrils, coughing, stretching of the neck, pain and distress.
  • Diagnosis: usually based on clinical signs, but further diagnostic tests may be necessary in some cases.
  • Treatment: many cases respond to medical treatment with sedatives and muscle relaxants. Some require nasogastric intubation and lavage. In a minority of cases this may be unsuccessful, and surgical treatment may prove necessary.
  • Prognosis: in most cases this is good, however it depends on the severity of the impaction and the time elapsed before veterinary attention is received.
Print off the Owner factsheet on Choke - oesophageal obstruction to give to your clients.

Pathogenesis

Etiology

  • Ingested material becomes impacted in esophagus.
  • Due to the shape of the esophagus, there are three main sites where this occurs:
    • At the thoracic inlet, as the esophagus curves up over the sternal notch to enter the thorax.
    • At the heart base, as the course of the esophagus changes direction to pass over the heart.
    • At the cardia and entrance to the stomach.

Predisposing factors

General

  • Feeding of inadequately soaked sugar beet pulp, which, when eaten, continues to swell, and can become impacted.
  • Feeding of inadequately chopped carrots, apples etc.
  • Feeding at irregular intervals, greed or competition from other horses can result in an individual eating too fast, insufficiently masticating their food, which may then become impacted.
  • Dental disease may also predispose to this condition if it results in inadequate mastication.
  • Presence of a neck swelling such as an abscess/cellulitis or even a neoplastic lesion may make it more difficult for food to pass, thus predisposing to esophageal impaction.
  • Esophageal strictures, diverticulum or megaesophagus will often predispose to recurrent choke Esophagus: stricture Esophagus: megaesophagus.
  • Presence of neurologic disease affecting the nerves involved in swallowing, such as guttural pouch mycosis Guttural pouch: mycosis or grass sickness Grass sickness.
  • Esophageal dysmotility.
  • Ingestion of foreign bodies - rare as horses are generally discriminate feeders.
  • Medication by boluses, particularly in small ponies.

Pathophysiology

  • Ingested food particles, or foreign bodies become impacted in the esophagus due to their size, due to swelling, or due to primary problems with swallowing and peristalsis.
  • Increased salivation is stimulated,
  • There is a tendency for food particles and saliva to pass down the nose.
  • The presence of impacted material in the esophagus causes pain and distress.
  • Coughing and aspiration pneumonia may occur.
  • Presence of obstruction in esophagus can, particularly if it continues to swell, cause pressure necrosis to the surrounding esophageal mucosa. Necrotizing esophagitis, ulceration, rupture or fistulation can follow.
  • Shallow mucosal ulcers tend to heal well, but deeper lesions can lead to stricture formation on healing which can predispose to future problems.
  • Aspiration of food particles can lead to the development of aspiration pneumonia Lung: pneumonia - aspiration.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Hepworth-Warren K L et al (2015) Intrathoracic oesophageal perforation and secondary pleuropneumonia: five cases. Equine Vet Educ 27 (6), 283-290 VetMedResource.
  • Viljoen A, Saulex M D & Steyl J (2012) Right subclavian artery anomaly in an adult Friesian horse. Equine Vet Educ 24 (2), 62-65 PubMed.
  • Terron-Canedo N, Compostella F, Hill A, Roberts V L H & Tremaine H T (2011) Case Report: Successful endoscopic removal of a foreign body in a young horse with oesophageal obstruction. UK Vet 16, 4-6 VetMedResource.
  • Chiavaccini L & Hassel D M (2010) Clinical features and prognostic variables in 109 horses with esophageal obstruction (1992-2009). J Vet Intern Med 24 (5), 1147-1152 PubMed.
  • Feige K, Schwarzwald C, Furst A & Kaser-Hotz B (2000) Esophageal obstruction in horses: a retrospective study of 34 cases. Can Vet J 41 (3), 207-210 PubMed.
  • Ramos J R, May K A & Crisman M V (2001) Complicated oesophageal obstruction in a stallion. Equine Vet Educ 13 (5), 235 VetMedResource.
  • Hillyer M H (1995) Management of oesophageal obstruction ('choke') in horses. In Pract 17 (10), 450-457 VetMedResource.

Other sources of information

  • Campbell N B (2003) Esophageal Obstruction (Choke). In: Current Therapy in Equine Medicine 5. Saunders. pp 90-94. ISBN: 072169540X.
  • Chaffin M K (1999) How I Treat Choke in Horses. In: Proc TNAVC. pp 81.
  • Rose R J & Hodgson D R (1993) Manual of Equine Practice. Saunders. ISBN: 0721637396.


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