Equis ISSN 2398-2977

Foal: neonatal regurgitation

Synonym(s): Dysphagia, milk regurgitation

Contributor(s): Virginia Buechner-Maxwell, Mary Rose Paradis

Introduction

  • The presence of milk in the nares of a newborn foal after nursing, is a sign of milk regurgitation in the foal. 
  • Milk regurgitation needs to be differentiated from external splashing of milk on the foals nose as a result of the streaming of milk from the mare.
  • Milk regurgitation is generally accompanied by aspiration pneumonia.
  • Cause: usually secondary to dysphagia from muscular or neurologic weakness of the pharynx but may be the result of anatomic abnormalities such as cleft palate, subepiglottic cyst, dorsal pharyngeal cyst, bilateral laryngeal paralysis.
  • Signs: milk in the nares after nursing, increased respiratory effort, increased auscultative pulmonary sounds, occasionally stridor and respiratory distress.
  • Diagnosis: history, clinical signs, upper airway endoscopy, thoracic radiographs.
  • Treatment: restrict nursing, provide nutrition via nasogastric intubation, broad spectrum antibiotics, if respiratory distress and stridor present then a tracheotomy may be necessary. Surgical removal of cyst if present. Treatment with vitamin E and selenium if secondary to deficiency.
  • Prognosis: good to guarded.

Pathogenesis

Etiology

Predisposing factors

General

Specific

Pathophysiology

  • Neurologic or muscular weakness may result in dorsal displacement of the soft palate and pharyngeal collapse.
  • Failure of the soft palate to form a seal with the dorsal pharyngeal wall - milk flows forward into nasal passage. 
  • Failure of epiglottis to seal larynx: milk is aspirated into the trachea and lungs, the caudal ventral portion of the lungs become consolidated; milk provides medium for bacterial growth and aspiration pneumonia   Lung: pneumonia - aspiration   ensues.
  • Negative pressure created pharynx by suckling may dynamically displace soft palate or collapse pharyngeal walls in the weak or premature foal.
  • Dorsal displacement of the soft palate is the most common cause of dysphagia and milk regurgitation in the neonatal foal.
  • If the dysphagia is secondary to prematurity, sepsis, perinatal asphyxia or myodegeneration then it will resolve as this primary problems resolve.
  • In cases of upper airway obstruction, the foal attempts to inhale and cant get enough air    →   stridor develops:
    • The presence of a pharyngeal cyst blocks the airway and disrupts the act of swallowing.
    • Paralysis of the larynx or arytenoiditis disrupts the proper closure of the larynx.
  • Cleft palate allows for milk to pass immediately from the oral pharynx to the nasopharynx.

Timecourse

  • Initially - milk appears in nares immediately after foal nurses.
  • Aspiration pneumonia develops over the course of a few days.
  • Upper airway obstruction: dysphagia, stridor and respiratory distress may be noted at birth and progress to aspiration pneumonia over course of 24-48 h.

Diagnosis

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Treatment

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Yarbtough T B, Voss E & Herrgesell E J (1999) Persistent frenulum of the epiglottis in four foals. Vet Surg 28 (4), 287-291 PubMed.
  • Altmaier K & Morris E A (1993) Dorsal displacement of the soft palate in neonatal foals. Equine Vet J 25 (4 ), 329-332 PubMed.
  • Barton M H (1993) Nasal regurgitation of milk in foals. Comp Cont Educ Pract Vet 15 (1), 81-90 VetMedResource.
  • Bowman K F, Tate L P, Evans L H et al (1982) Complications of cleft palate repair in large animals. JAVMA 180 (6), 652-657 PubMed.
  • Dill S G & Rehbun W C (1985) White muscle disease in foals. Comp Cont Educ Pract Vet (11), 627-635 VetMedResource.
  • Stick J A & Boles C (1980) Subepiglottic cyst in three foals. JAVMA 177 (11), 62-64 PubMed.
  • Balstone J H K (1966) Cleft palate in the horse. Br J Past Surg 19, 327 PubMed.

Other sources of information

  • Paradis M R (2006) Aspiration Pneumonia Secondary to Dysphagia. In: Equine Neonatal Medicine: A Case Based Approach. Ed: Paradis M R. Elsevier, USA.


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