Female urogenital surgery

How to – Caslick’s suture


A Caslick’s suture is used in mares to treat vulvar trauma, pneumovagina, vaginitis and infertility. It should not be used if splanchnoptosis is severe and the Caslicks would impair urine flow.

A deep (thick) Caslick’s may be used as a permanent means of preventing vaginal prolapse.

Relevant anatomy

The vulvar lips comprise the first barrier to the uterus. If the vulvar lips do not seal totally, a Caslick’s suture is placed to create the seal.

Preoperative management

Food restrictions: NA

NSAIDs/analgesics: NSAIDs are recommended preoperatively.


Tetanus prophylaxis is recommended. 

Local blocks: Typically a line block on each side of the vulva is performed.

Position/preparation: The patient is sedated as needed and restrained in stocks (mares) or headgates (cattle).  Sterile gloves are recommended.

Surgery Supplies: 

  • Scalpel blade and handle
  • Metzenbaums
  • Suture scissors
  • 2-0 suture on a cutting needle

Surgical procedure

A thin strip of tissue is removed from each side of the vulva at the mucocutaneous junction, extending from the dorsal junction to the pelvic brim (approximately 2/3 of the length). The cut edges are sutured together using a split thickness Ford Interlocking or continuous pattern of 2-0 absorbable or nonabsorbable suture material. Due to the local block, bites should be taken closely together (1/2 cm) and pulled snugly to prevent gaps.

Split thickness suturing

Postoperative care

  • Sutures are removed in 10-14 days.
  • Episiotomy (cut the Caslick’s) is performed to open the Caslick’s prior to parturition


  • Gaps may develop between the vulvar lips if the suture pattern is too loose.
  • Natural breeding with the vulvar lips closed can lead to trauma to the mare and/or stallion
  • Foaling through the closed vulva can lead to trauma to mare and/or foal
  • Each time the Caslick’s is replaced, it becomes thicker and harder to create a seal.


Equine Caslicks – with poor instrument handling but nice visuals


Manual of Clinical Procedures in the Horse


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Large Animal Surgery - Supplemental Notes Copyright © by Erin Malone, DVM, PhD is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.