Surgery of the Equine Female Reproductive Tract

Question 1

Describe the reproductive anatomy/conformation of the vulva

Answer 1

Labia
- Vertically orientated
- 2/3rds vulvar opening below floor of pelvis
Upward orientation of vestibular opening
- If horizontal orientation – contamination
Poor conformation is often acquired: Injury, age, parity, body condition

Question 2

Name the 3 anatomical barriers – help to stop bacteria/infections getting into the uterus

Answer 2

Vulva
Vestibulovaginal fold
Cervix

Question 3

List some conformation Problems Contributing to Poor Reproductive Performance in mares (where the surgeon can help)

Answer 3

1. Pneumovagina - Caslicks
2. Perineal reconstructions - Gadds
3. Urovagina - Urethral extension
4. Cervical incompetency - Cervical repair
5. Delayed uterine clearance - Uterine suspension
6. Oviduct blockage - Oviduct lavage, Prostaglandin

Question 4

Describe the use of the caslicks procedure

Answer 4

Improved vulvar competence; reduced pneumovagina

Question 5

Describe how to perform the Caslicks procedure

Answer 5

1. Stocks / against doorway
2. Tail bandaged & held out of the way
3. Wash perineum
4. Local anaesthesia
5. Excise thin band of mucosa each side (3-4mm)
   - Include dorsal commissure
   - Level with the ischiatic tuber
   - Do not oversuture
   - Usually 0USP (3.5M) non-absorbable monofilament suture
6. Remove sutures 10-14 days later
7. Remove Caslick before foaling

Question 6

Describe the uses of perineal body reconstructions

Answer 6

More severe cases of pneumovagina
Second degree perineal lacerations

Question 7

When is urovaginal most commonly seen?

Answer 7

Urine in the vagina
Usually seen in old, multiparous mares
Often with pneumovagina

Question 8

How is a diagnosis of urovagina confirmed?

Answer 8

Cytology

Question 9

How is urovagina treated?

Answer 9

Improve body condition if thin
Surgical management:
- Caudal relocation of the transverse fold
- Urethral extension

Question 10

When do cervical injuries most commonly occur?

Answer 10

During parturition

Question 11

How are cervical lacerations treated?

Answer 11

Surgery during dioestrus >3weeks post-partum
Requires good set-up and assistance

Question 12

Delayed uterine clearance can lead to?

Answer 12

Endometritis
Post mating persistent endometritis

Question 13

How is delayed uterine clearance treated?

Answer 13

Treatment is uterine suspension (uteropexy)
- Restoration of horizontal orientation of uterine horns
- Improves uterine clearance
- Improves perineal conformation
- May reduce urine pooling

Question 14

How is an oviduct blockage treated?

Answer 14

Laparoscopic injection of prostaglandin:
- Relaxes smooth muscle of oviduct
- Modulates oviductal transport

Question 15

Describe 1st degree perineal lacerations

Answer 15

Mucosal damage
Caslick/no surgery required

Question 16

Describe 2nd degree perineal lacerations

Answer 16

Mucosa, submucosa & perineal muscles
Caslick’s procedure & reconstruction of the perineal body

Question 17

Describe 3rd degree perineal lacerations

Answer 17

Complete disruption of rectovestibular shelf, perineal body & anus
Faecal contamination
Requires surgical repair

Question 18

Describe surgery for 3rd degree perineal lacerations

Answer 18

Delay repair for 4-6 weeks
Need swelling to go down
Need to get this mare on a laxative diet
One and two stage procedures described

Question 19

What is the cause of a rectovestibular fistula

Answer 19

Penetration of foals foot into rectum without progression to 3rd degree perineal laceration

Question 20

What are varicosities and how is it treated?

Answer 20

Intermittent vulvar bleeding
Blood pooling
Worst at oestrus
Treatment:
- Not always necessary
- Topical treatment with astringent creams
- Ligation
- Cautery
- Laser photocoagulation

Question 21

Name the most common neoplastic disorder of the ovaries in mares

Answer 21

Granulosa (Theca) Cell Tumour (GCT)

Question 22

Describe the main features of a Granulosa (Theca) Cell Tumour (GCT)

Answer 22

Unilateral (can be bilateral)
Rarely metastasise
Good prognosis after removal
Behavioural signs:
- Anoestrus / continuous oestrus
- Stallion like behaviour / aggression

Question 23

How are granulosa cell tumours in mares diagnosed?

Answer 23

1. Rectal examination
   - Enlarged ovary on affected side
   - Contralateral ovary usually small
2. Transrectal ultrasonography - Distinctive honeycomb like appearance
3. Endocrinology

Question 24

How is endocrinology testing used to diagnose granulosa cell tumours in mares?

Answer 24

↑Testosterone in 50%
↑Inhibin in 85%
↑ Anti-Müllerian Hormone (AMH) in 98%

Question 25

What is a ‘red bag delivery’ ?

Answer 25

Placenta has prematurely detached from the uterus, foal is no longer sustained

Question 26

How will a mare with dystocia present?

Answer 26

• Prolonged discomfort & straining
• Straining without appearance of amnion
• Appearance of amnion / head / limb but no further progress

Question 27

Describe the approach to a mare with dystocia

Answer 27

• Be as quick and thorough as you can!
• Obtain a succinct history
• Clinical exam

Question 28

Describe how to perform a clinical exam in a mare with dystocia

Answer 28

Time yourself – should take <15 minutes!
Standing / recumbent
What state is the mare in (shock, haemorrhage)?
+/- sedation - xylazine
Bandage the tail
Clean the perineum
Wash your hands and arms
Use adequate lubricant
Establish if foal is alive or not

Question 29

What are the treatment options for dystocia?

Answer 29

Assisted vaginal delivery
Controlled vaginal delivery
Caesarian section
Embryotomy

Question 30

Describe assisted vaginal delivery

Answer 30

• Mare is conscious (usually standing)
• Foal delivered using traction +/- ropes
• Similar approach as for cattle & sheep but less room and more straining
• Sedation & epidural

Question 31

Describe controlled vaginal delivery

Answer 31

• Mare is anaesthetised +/- hindlimbs elevated
• Foetus delivered per vagina
• Can be done on the premises if referral is not an option
• In clinic facilities, the abdomen should also be prepared for a caesarean section

Question 32

How long should a horse be hospitalised post c-section?

Answer 32

1 week

Question 33

Is the foal or mare more important to save in a c-section?

Answer 33

• Foal more important than saving the mare (foal priority)
• Chronic disease in the mare
• Deliver foal under anaesthesia then euthanise the mare
• Owners must be aware of the implications of rearing an orphan foal / organise a foster mare

Question 34

List the possible complications that can occur following dystocia/parturition

Answer 34

• Uterine prolapse
• Uterine rupture
• Uterine haemorrhage
• Invagination / retroflexion of the uterine horn
• Retained foetal membranes
• Cervical tears
• Perineal lacerations / rectovaginal tears

Question 35

How is uterine prolapse treated?

Answer 35

Replacement under standing sedation / GA

Question 36

Describe uterine torsion in mares

Answer 36

Uncommon
Diagnosed on rectal palpation
Last 2 months gestation / at parturition
Colic / dystocia
Correction: surgical / rolling

Question 37

Describe uterine rupture in mares

Answer 37

Clinical signs evident 24 – 72 days post foaling
Clinical signs and treatment depend on size of tear