Horse Project Week 1 - Examine external genitalia

External Genitalia

The external portion of the mare reproductive tract includes the vulva and clitoris. The conformation of the perineal area is important because the labia lips are the first barrier to introduction of debris into the reproductive tract (windsucking) and gives clues to the vaginal tilt and possible problem of urine pooling in the vagina.

Surgical correction for conformation problems is possible: Caslick's closure of the vaginal lips (windsucking), episioplasty and urethroplasty (urine pooling) are common surgeries.

Below is the list of observations that should be made about the external genitalia.

• Is there any discharge? 
• What is the vulvar conformation? 
• The vulva should be perpendicular to the ground with >70% of the vulva below the ischium.
• The labia should form a good seal and close completely.
  • The "windsucker" test, performed by parting the vulvar labia and listening for an inrush of air, tests the integrity of the vaginal vestibular sphincter. 
  • Older, thin mares with a flat croup and atrophy of vulvar lips are more prone to pneumovagina.

Pictures of mare external genitalia
Mare external genitalia exam ( Video 1 & Video 2 )

	The ischium are the bones that form the bottom of the pelvis. The area outlined in red will be the bones that you are palpating to detemine how much vulva is below the ischium. In this mare, only 25% is below the ischium. It is impossible to determine where the pelvic floor is unless you palpate the area.
Examples:
Mare with Good external conformation (perpendicular to the ground and 70% below ischium).	Sunken anus in an aged mare, increased incidence of fecal contamination of the vulva/ vagina. Fair external conformation (slightly angled to the ground and >70% below ischium)
Caslick's ligature (below) : Used to close the vulva in mares that have loose labia lips which allow air and debris to enter the vagina (windsucking). These mares are prone to pneumovagina. Air (and bacteria) are sucked into the vagina and may colonize the cervix and internal reproductive tract leading to endometritis (infection of the uterus). The Caslick's must be removed before parturition and may need to be removed for breeding. Many performance and racing mares have Caslick's although they are not used for breeding (Always check for a Caslick's).