Equine Reproductive Procedures. Группа авторов

Equine Reproductive Procedures

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.).

12 Uterine Culture Collection: Swab/Brush

John J. Dascanio

School of Veterinary Medicine, Texas Tech University, USA

Introduction

Culture of the uterus is performed as part of the routine mare breeding soundness examination. It is also performed as part of an infertility workup, or upon request by a stallion owner prior to breeding, or as surveillance for disease. Culture may be performed via a standard uterine culture swab, from secretions obtained from a uterine brush, from a uterine biopsy, or from fluid obtained from a low volume uterine lavage.

The method for performing a uterine culture depends on a number of factors, such as cost, time to perform the procedure, and availability of equipment. Generally, a guarded or double‐guarded swab or brush is routinely used to obtain a sample for culture, while a low volume uterine lavage would be indicated for an infertility workup in a problem mare or in a mare that is suspected of an infection, but has had a negative uterine swab/brush. With persistent or chronic infections, culture of a uterine biopsy may be warranted.

The best time to perform a uterine culture may be debatable, but is most often performed in early estrus. Cultures may be performed in diestrus, but prostaglandins should be administered after the collection procedure to lyse any luteal tissue and bring the mare into estrus, so that any contaminants introduced during the procedure may be eliminated.

Culture swabs should be immediately plated onto blood agar or other appropriate microbial culture media. If a culture swab is transported to a laboratory, it should be held at refrigerator temperature to prevent overgrowth of contaminants.

Equipment and Supplies

Tail wrap, tail rope, non‐irritant soap, roll cotton, stainless steel bucket, disposable liner for bucket, paper towels, sterile lubricant, sterile obstetrical sleeve, guarded culture device (Kalayjian swab, single‐guarded (Figure 12.1); McCullough swab, double‐guarded (Figure 12.2); or uterine brush, guarded (Figure 12.3)), aerobic bacterial transport device.

Technique

Remove feces from the rectum.

Place a tail wrap and tie the tail out of the way (see Chapter 4).

Clean and dry the perineum of the mare (see Chapter 3).

Place a sterile obstetrical sleeve on the arm.

Place the guarded culture device into the palm of the hand.

Place sterile lubricant on the knuckles and down the length of the sleeve being careful not to get lubricant onto the palm. If the culture device becomes inundated with lubricant, it may be more difficult to obtain a

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Equine Reproductive Procedures. Группа авторов