Equis ISSN 2398-2977

Vestibule: urine pooling

Contributor(s): Terry Blanchard, Graham Munroe, Sarah Stoneham, Madeleine L H Campbell

Introduction

  • A pool of urine collects cranially in the vagina, sometimes partially covering the cervix and flowing into the uterus, particularly when the cervis is relaxed during estrus.
  • Cause: conformational defects, age, weight loss, previous trauma to the reproductive tract during dysocia, iatrogenic as the result of over-zealous Caslick's operations in which the vulva has been sutured too low.
  • Signs: acute vaginitis, cervicitis and endometritis. Usually prevents conception.
  • Diagnosis: vaginoscopy, manual palpation of the vagina and rectal palpation, ultrasonography.
  • Treatment: some resolve spontaneously; medical treatment, surgical creation of a mucosal tube to effectively extend the urethra caudally.
  • Prognosis: fair in young mares, or following surgery.

Pathogenesis

Etiology

  • Poor conformation of the vulva.
  • Large uterus dragging posterior vagina forward especially when the anus is positioned cranial to the labia (pendulous abdomen).
  • Breeding and/or foaling injuries result in stretching/tearing/scarring of vulva/vestibule/perineal body.
  • Iatrogenic as the reslt of over-zealous Caslick's operations Vulva: Caslick operation in which the vulva has been sutured too low, inhibiting normal efflux of urine from the vagina through the vulval lips.

Predisposing factors

General

  • Multiparity.
  • Old age.
  • Large uterus.
  • Poor post-partum uterine involution.
  • Breeding or foaling injury.
  • Weight loss.
  • Tall thin mares with flat croup, high tailhead.
  • Reduced vulval orifice in Caslicked mare.

Pathophysiology

  • Factors that affect the integrity of the vulva or vestibulovulvar sphincter predispose to pooling of urine in the cranial vaginal vault.
  • Poor conformation → change in angle of pelvic floor → urine drains cranially.
  • Usually in older multiparous mares → large pendulous uterus drags posterior vagina forward → forward and downward angle of anterior vagina and cervix.
  • May be temporary in some mares at first post-partum estrus → resolves as uterus returns to normal size.
  • Reduced vulval opening in Caslicked mare Vulva: Caslick operation may result in urine being splashed back cranially.
  • Urine pooling → acute vaginitis Vagina: bacterial infection, cervicitis, and endometritis Uterus: endometritis - bacterial.

Timecourse

  • May be gradual as mare ages, or temporary.

Diagnosis

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Schnobrich M R, Gordon D L, Scoggin C F, Bradecamp E A & Canisso I F (2017) Creatinine concentrations of accumulated intrauterine fluid to confirm the clinical diagnosis of urometra in mares. Vet Rec 180 (12), 304 PubMed.
  • Pollock P J (2012) A fresh look at vesicovaginal reflux in mares. Vet Rec 170 (24),618-619 PubMed.
  • Prado T M, Schumacher J, Kelly G M & Henry R W (2012) Evaluation of a modification of the McKinnon technique to correct urine pooling in mares. Vet Rec 170 (24), 621 PubMed.
  • Jalim S L & McKinnon A O (2010) Surgical results and fertility following correction of vesicovaginal reflux in mares. Aust Vet J 88 (5), 182-185 PubMed.
  • McKinnon A O et al (1988) A urethral extension technique to correct urine pooling (vesticovaginal reflux) in mares. JAVMA 192 (5), 647-650 PubMed.
  • Brown M P et al (1978) Urethral extension for treatment of urine pooling in mares. JAMVA 173 (8), 1005-1007 PubMed.


ADDED