Mare Urogenital Surgery

Question 1

What are the 3 major protective barriers in the caudal reproductive tract of mares? What happens if any of these are damaged?

Answer 1

1. constrictor vulvae muscles of the labia
2. vestibular sphincter
3. cervix

contamination of the repro tract –> infertility

Question 2

What are 3 aspects of proper vulvar conformation in mares?

Answer 2

1. vertical in craniocaudal plane
2. approximately 2/3 should sit below ischial arch
3. muscular labia should resist separation

Question 3

In what mares is poor vulvar conformation common? What are 2 common findings? What can this lead to?

Answer 3

thin, multiparous mares

1. sunken anus
2. loss of vulvar constrictor muscle tone

pneumovagina (windsucker), fecal contamination, urine pooling

Question 4

What are 2 indications of Caslick’s procedure?

Answer 4

(vulvoplasty)

1. pneumovagina
2. fecal contamination of the caudal repro tract

Question 5

How is Caslick’s procedure performed? What is recommended in pregnant mares?

Answer 5

trim a small amount of tissue from the mucocutaneous junction and use 2-0 monofilament suture material to bring them together in a simple continuous or Ford interlocking pattern

remove 2-4 weeks before foaling –> replaced next year

Question 6

What does excessive closure in Caslick’s procedure lead to? Excessive trimming of mucocutaneous junction?

Answer 6

urovagina - should be able to pass a tube speculum

less tissue available for following years

Question 7

What are the 2 goals to perineal body reconstruction? What does this result in?

Answer 7

1. restore integrity of DORSAL aspect of vestibule and vestibular sphincter function
2. make vulva more vertical

perineal body remains intact, only mucosa and submucosa are transected

Question 8

What are the 2 goals of perineal body transection? What does this result in?

Answer 8

1. more vertical position of vulva
2. correct pneumo and urovagina

horizontal incision between rectum and vulva extend cranially through muscles of the perineal body

Question 9

What are 3 causes of urovagina? What sequelae are associated?

Answer 9

1. cranial vaginal slopes ventrally, common in thin, multiparous mares
2. excessive Caslick’s closure
3. ectopic ureter

vaginitis, cervicitis, endometritis, infertility

Question 10

What is the treatment of choice for urovagina? What sequelae is common?

Answer 10

urethral extension –> caudally

fistula formation

Question 11

What are 3 indications for equine ovariectomies?

Answer 11

1. behavior modification
2. sterilization
3. ovarian neoplasia (GCT), cysts, hematomas, or abscesses

Question 12

What 3 signs are associated with granulosa cell tumors? What are 3 options for diagnosis?

Answer 12

anestrus, nymphomania, stallion-like behavior

1. affected ovary is enlarged, contralateral is small and inactive
2. honeycomb appearance on U/S
3. increased testosterone and inhibin levels

Question 13

What are 3 options for ovariectomy procedures?

Answer 13

1. colpotomy
2. laparotomy - stanking flank, ventral celiotomy (midline, paramedian, diagnoal paramedian)
3. laparoscopy

Question 14

In what ovaries are colpotomies recommended? What kind of procedure is this?

Answer 14

normal ovaries

standing, blind procedure

Question 15

Where is the incision made in a colpotomy?

Answer 15

though vagina into the abdomen at 11 and 1 o’clock cranial to the cervix

Question 16

How is a colpotomy performed?

Answer 16

• place lidocaine-soaked gauze around the mesovarium
• remove ovary with an ecraseur, which passes a chain over the ovary and tightens –> crushes and cuts
• incisions heal by second intention

Question 17

What 3 complications are associated with colpotomies?

Answer 17

1. adhesions
2. evisceration - increased pressure when horse gets up from laying down, must keep horse standing 3-5 days post-op
3. fatal hemorrhage from ovarian pedicle (branch of urogenital artery)

Question 18

What kind of procedure is a laparotomy? In what ovaries is this procedure recommended for?

Answer 18

standing flank, blind or laparoscopic-assisted

<20cm, unilateral

Question 19

What 3 approaches are used for ventral laparotomies? In what ovaries is this recommended?

Answer 19

1. midline
2. paramedian
3. diagonal paramedian

normal to very large - >20cm (GCT)

Question 20

What are 5 advantages to performing a laparoscopy during ovariectomies?

Answer 20

1. can be unilateral or bilateral
2. direct visualization
3. can remove large ovaries
4. avoids general anesthesia
5. minimal tension on pedicle

Question 21

What are 5 disadvantages to performing a laparoscopy during ovariectomies?

Answer 21

1. flank incision is more likely to develop seroma and dehiscence
2. bowel or splenic puncture possible
3. causes retroperitoneal insufflation
4. hemorrhage
5. post-op pain, colic

Question 22

What is indicative of uterine torsion in mares?

Answer 22

• colic in periparturient mares, most common in the last 60 days of gestation
• acute presentation

Question 23

How is uterine torsion diagnosed? What affects prognosis?

Answer 23

rectal palpation - broad ligament toward the side of rotation, most commonly precervical so a vaginal exam will be normal

improved if earlier in gestation

Question 24

How are uterine torsions medically managed? When does it work most? What complication is possible?

Answer 24

rolling in the direction of the torsion, use board to hold gravid uterus in place (GA!)

pre-term pregnancies

uterine rupture

Question 25

What are 2 approaches used for surgically treating uterine torsion?

Answer 25

VENTRAL MIDLINE - recommended if foal is deceased or uterus is devitalized/ruptured (colic signs) STANDING FLANK - standing sedation, incision on the side of the torsion, lift and rotate uterus upward OR incision on the opposite side and pulling toward surgeon

Question 26

What should be done on presentation in cases needing C-sections?

Answer 26

- quick PE and rectal - place catheter - get owner consent - U/S for fetal viability PROMPT REFERRAL

Question 27

What approach is performed for equine C-sections? What is necessary to perform on the uterus? What sequela is common?

Answer 27

ventral midline hemostatic sutures --> diffuse placental attachment, left in place to pass later retained placental membranes

Question 28

In what mares are perineal lacerations most common? What are the 3 degrees?

Answer 28

unassisted foalings, primiparous mares 1. skin of dorsal commissure and mucosa of vestibule 2. continue into muscles of the perineal body 3. complete disruption of rectovestibular shelf

Question 29

How are each degree of perineal lacerations treated?

Answer 29

1. typically no surgical intervention needed +/- Caslisk's procedure 2. Caslick's procedure, reconstruction of perineal body - predisposed to pneumovagina and urine pooling without correction 3. REQUIRES surgery

Question 30

When are 3rd degree perineal lacerations repaired? What is seen in acute tears?

Answer 30

MUST wait for stong scar tissue to develop - 6-8 weeks (3-4 minimum) - fecal contamination - edema - questionable tissue viability (high % of repair failure)

Question 31

In what 3 ways are mares prepared for third degree perineal laceration repair? When is surgery delayed?

Answer 31

1. reduce feed prior to surgery 2. allow grass with laxatives after surgery 3. tube with mineral oil/Epsom salts delay surgery if feces are not soft

Question 32

What are rectovaginal fistulas? When do they most commonly happen? How are they repaired?

Answer 32

communication between rectum and vaginal vault foal limbs replaced after puncturing through rectum direct suturing, converting into a 3rd degree perineal lacreation repair

Question 33

How do uterine tears present? What causes them at different locations in the reproductive tract?

Answer 33

signs of septic peritonitis --> can result in evisceration during or after foaling due to prolapsed abdominal organs - tip of uterine horns - perceived normal foaling, foal kicking hind limbs - uterine body - dystocia

Question 34

When are cervical lacerations most commonly seen? How are they diagnosed?

Answer 34

dystocia, especially with fetotomy or induced parturition examine cervix 21 days post partum - inflammation and edema makes it hard to see day of

Question 35

What does cervical laceration lead to? When is surgery required?

Answer 35

infertility of >50% torn --> 3 weeks postpartum or immediately after rebreeding

Question 36

What is the most common cause of death in postpartum mares? In what mares is this most common? How do mares present?

Answer 36

broad ligament / uterine artery rupture older mares colic followed by signs of blood loss

Question 37

What are 3 other common foaling injuries?

Answer 37

1. bladder rupture or eversion - manually reduce 2. rectal prolapse 3. mesocolon rupture - severe colic, requires R&A

Question 38

What are the 2 most common postpartum uterine conditions?

Answer 38

1. uterine prolapse - rare in mares 2. retained fetal membranes - >4 hours, requires prompt and aggressive treatment before laminitis develops