Equis ISSN 2398-2977

Urachus: patent

Introduction

• Cause: congenital and acquired forms of failure of the urachus to occlude at the umbilicus.
• Acquired types may be associated with systemic debilitation and/or umbilical infection.
• Signs: Presents within first 2 weeks of life with moist umbilicus and leakage of urine from the patent urachus.
• In acquired forms may be severe systemic signs in compromised neonatal foal.
• Diagnosis: history, signs.
• Treatment: is usually medical with antibiotic therapy, local umbilical cleaning/skin protection, possibly cautery, primary problem care and surgical resection of the umbilical remnants with persistent cases.
• Prognosis: guarded in systemically ill foals.

Pathogenesis

Etiology

• Congenital or acquired.

Pathophysiology

• Urachus never closes at birth.
• Unknown etiology possibly due to distention from cord torsionin uteroor during delivery leading to tension of the umbilicus, dilation of the urachus and preventing occlusion.
  Acquired urachus syndrome
• Re-opens post-partum as the dried umbilical stump falls off.
• Associated with umbilical infection/inflammation or excessive use of concentrated iodine dip resulting in premature sloughing of umbilical stump.
• Excessive wetness or trauma to the umbilical stump in the recumbent foal.
• Prolonged recumbency in debilitated foal.
• Poor/inexperienced cord ligation or severance. Ligature, if not removed may result in premature sloughing of stump.
• Any cause of increased intra-abdominal pressure, eg meconium retention   Rectum: meconium impaction  (tenesmus, dysuria etc).
• Urine leakage   →   persistent irritation and potential source of infection.

• Congenital forms are present at birth.

Timecourse

• Acquired forms develop in the first 2 weeks of life.

Diagnosis

Treatment

Prevention

Outcomes