Equine Reproductive Procedures. Группа авторов
then pelvic brim and past the vestibulo‐vaginal fold. The tri‐valve Polansky (Caslick) is advanced into the vagina and then opened by twisting the wing nut to extend the three arms outward (Figure 10.3).
Some resistance will be encountered at the level of the vestibulo‐vaginal fold. Slight forward pressure with some slight rotation will allow the speculum to enter the vagina.
A light source is used to visualize the walls of the vagina and the cervix. The tube speculum may need to be moved in all directions and pushed inward or pulled outward to visualize all structures.
Any purulent discharge should be sampled using a sterile uterine culture swab and submitted for bacterial/fungal identification in appropriate transport media.
Visualization should continue while the tube speculum is removed from the vagina and vestibule.
Interpretation
The vaginal membranes and cervix should appear as per the stage of the mare’s estrous cycle.
There should not be a purulent discharge from the cervix (Figure 10.4).Figure 10.4 Discharge through the external os of the cervix in a mare with a pyometra.Figure 10.5 Urine in the cranial vaginal vault.
There should not be any fluid accumulation on the floor of the vagina (Figure 10.5).
No defects should be noted in the vagina or cervix such as adhesions, tissue disruption, or masses (Figure 10.6)Figure 10.6 Adhesions covering the cervix of a mare secondary to a dystocia.
The speculum should be examined upon removal for any abnormal discharges present on its surface.
Further Reading
1 Dascanio JJ. 2011. External reproductive anatomy. In: McKinnon AO, Squires EL, Vaala WE, Varner DD (eds). Equine Reproduction, 2nd edn. Ames, IA: Wiley Blackwell, pp. 1577–81.
2 Pascoe RR. 1979. Observations on the length and angle of declination of the vulva and its relation to fertility in the mare. J Reprod Fertil Suppl 27: 299–305.
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