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11 Digital Examination of the Vagina/Cervix

Sofie Sitters

Amsterdam, The Netherlands

Introduction

Digital examination of the vagina and cervix is indicated when performing a breeding soundness examination on a mare and typically will be performed in conjunction with a speculum examination of the vagina and cervix. Unfortunately, digital examination of the cervix is often overlooked, rushed, or incompletely performed, although cervical abnormalities are a known cause of chronic infertility. A visualization of the cervix and external cervical os alone is insufficient to diagnose all cervical abnormalities. Digital palpation of the vagina and cervix will provide detailed information on subtle changes within the vaginal vault and will permit a more complete assessment of abnormalities of the external cervical os and the cervical lumen.

Thorough evaluation of the cervix is indicated in determining if a mare will make a suitable embryo transfer recipient. In these cases a digital examination of the cervix is important to establish if transcervical transfer of an embryo will be possible and if the cervix will functional normally to help maintain the ensuing pregnancy.

Digital examination of the vagina and cervix may also be indicated in postpartum mares in order to diagnose vaginal or cervical trauma. Cervical lacerations may occur during dystocia or during an apparently uneventful delivery. Pathology that may be detected with a manual examination includes lacerations, scar tissue formation, adhesions, fistula formation, cervical incompetence, tissue trauma, subcutaneous masses, and retained fetal membranes.

Palpation and ultrasonography of the reproductive tract per rectum is recommended prior to digital examination of the vagina and cervix to confirm that the mare is not pregnant. Performing vaginal examination in pregnant mares should be avoided as it may disrupt the natural mucosal seal and an iatrogenic ascending infection is a potential risk. In addition, manipulation of the cervix should be avoided in the late term pregnant mare due to the possibility of stimulating prostaglandin release and subsequent triggering of uterine contractions.

Stage of Cycle

The goal of the exam dictates whether digital palpation of the vagina and cervix should be performed during estrus or diestrus. A digital examination of the vagina and cervix during estrus is indicated in the assessment of fertility in older maiden mares since failure of cervical relaxation is one factor attributed to reduced fertility. If reproductive failure due to a cervical laceration and/or adhesion is suspected, the examination is best conducted during diestrus when the cervix is normally closed under the influence of progesterone. A digital examination during diestrus allows assessment of the ability of the cervix to close and protect the uterus and a possible pregnancy from the external environment.

In the event of dystocia or other difficult birth, the examination is performed immediately after foaling to evaluate the cervix and vaginal vault for trauma.

Equipment and Supplies

Tail wrap, tail rope, non‐irritant soap, roll cotton, stainless steel bucket, disposable liner for bucket, paper towels, examination gloves, obstetrical sleeve, sterile water‐soluble lubricant, surgery gloves.

Technique

Remove feces from the mare’s rectum.

Place a tail wrap and tail rope on the mare (see Chapter 4).

Wearing examination gloves, clean and dry the perineum of the mare (see Chapter 3). Wear a clean obstetrical sleeve (turn inside‐out) or a sterile obstetrical sleeve and apply sterile lubricant on the knuckles. A (sterile) surgeon’s glove may be applied over the sleeve to aid in a more detailed palpation. The fingers of the obstetrical sleeve may be cut off with scissors before applying the surgeon’s glove.

Apply lubricant from the knuckles onto the vulva.

Pass the fingers through the vulvar labia vertically and enter the vagina with a rotating movement, spreading lubricant on the inside of the vulva and preventing inward pulling of the vulvar lips and ventral aspect of the anal sphincter into the vagina. Avoid rubbing the hand or arm on the clitoris as this area harbors many bacteria.

The vestibular vault will be entered first and has a ventro‐dorsal slope. About wrist deep, the transverse vestibulo‐vaginal fold will be passed and some resistance may be encountered in normal mares whilst doing so. This fold is a remnant of the hymen, which partitioned the vestibule from the vagina proper. It may extend for a variable distance up the lateral walls, and occasionally a persistent hymen is present.

The external urethral orifice is located on the ventral midline under the transverse fold. Care should be taken not to dilate the opening with a finger or confuse it as being a continuation of the vagina or as being the external cervical os.

The entire vaginal wall can be palpated using a flat hand in a systematic manner. Any abnormalities in the vaginal mucosa and vaginal musculature should be noted.

Advance the hand cranially to the end of the vagina and locate the cervix and external cervical os. Insert the index finger into the cervical lumen and advance cranially evaluating tone, internal diameter, and direction of the cervical canal entering the uterus.

Pull the index finger back to the level of the external cervical os and hold the opposing thumb on the outside of the cervical wall opposite the index finger. Exert slight compression between the two fingers on the cervical tissue in between them. Either rotate the two fingers together 360 degrees or rotate 180 degrees and then insert the thumb into the lumen, palpating the other half of the cervix between the thumb and opposing index finger on the outside of the cervix. Evaluate the complete vaginal/cervix area systematically to detect intravaginal and intracervical trans‐luminal abnormalities.

Interpretation and Additional Comments

In estrus, the vaginal and cervical surfaces will be moist and edematous. The cervix will be softened and dropped toward the vaginal floor. In diestrus, the cervical and vaginal surfaces will be dry and the external cervical os will project into the cranial vagina from high on the wall and is tightly contracted.

The vestibulo‐vaginal junction should be closed. However, if the examiner’s hand slips easily into the anterior vagina, the mare may be predisposed to pneumovagina (see Chapter 5).

The vaginal wall should be smooth and supple and lined by smooth vaginal mucosa. Vaginal trauma from a previous foaling or, less frequently, breeding accidents, might have caused vaginal scarring and adhesions, presenting as irregularities in the vaginal lining. Formation of scar tissue within the vaginal canal can be very extensive following dystocia and may nearly obliterate the vaginal canal, making vaginal penetration impossible in extreme cases. Scar tissue will feel firmer and non‐confluent with the surrounding vaginal mucosa.

Lacerations and tears of the vaginal wall may be present, caused by dystocia. In the case of small lesions, these may be felt more easily than seen. Fingers may slide into a blind pouch in the vagina where a fistula may be present from a foaling injury. These may occur with a direct communication to the rectum, into the retroperitoneal space or into the peritoneal cavity. Fistulas are more likely to enter the peritoneal cavity with a lesion of the cranial vagina or cervix and may result in peritonitis. Masses within the wall of the vagina may be hematomas related to trauma, abscessation, or tumor formation (e.g., leiomyoma).

In maiden mares the hymen area should be palpated to ensure the absence of tissue bands formed by hymen remnants since these bands may contribute to a recto‐vaginal perforation at parturition. However, these bands typically have no effect on fertility. Depending on the thickness and toughness of the hymen, it can be broken down easily with firm, steady pressure and digital dilation (see Chapter 6).

Scars, adhesions, and lacerations may also involve the cervix. Cervical lacerations may involve the external os only or the entire length of the cervix. As long as the cervix has the ability to open and close normally, small tears in the os are usually of minor importance. However, large lacerations involving the external os or the entire cervix are more significant and may require surgery to repair, restoring the cervical barrier to infection.

Upon removal of the gloved hand from the vagina, the hand should be observed for abnormal discharges (purulent, bloody, etc.) or odors (infectious, necrotic, urine, etc.).