Surgery of the Equine Male Reproductive Tract

Question 1

Testis passes into the inguinal canal at … days gestation

Answer 1

270-300

Question 2

What is the gubernaculum?

Answer 2

Gob is to get the testicles from up by the kidneys all the way down to the scrotum

Question 3

What are the cranial, middle and caudal parts of the gubernaculum?

Answer 3

Cranial - proper ligament of the testis
Middle – ligament of the tail of the epididymis
Caudal – scrotal ligament

Question 4

What are the 3 indications for castration in males?

Answer 4

Prevent breeding
Modify behaviour
Neoplasia / inguinal hernia

Question 5

What are the considerations for castration in males?

Answer 5

Age
Breed / size
Temperament
Season

Question 6

Describe the pre-operative assessment of males before castration

Answer 6

History - Previous scrotal / inguinal hernia
Good restraint essential
Clinical examination
Auscultation of the heart
Palpation

Question 7

Why is palpation an essential part of the pre-operative castration assessment?

Answer 7

Are both testes palpable? – cannot castrate unless the answer is yes
Are any hernias palpable?

Question 8

What are the options for castration?

Answer 8

Standing sedation vs. general anaesthesia
Field anaesthesia vs. GA under theatre conditions

Question 9

Describe the steps to prepare for standing sedation castration

Answer 9

• Sedation (α2 agonist & opiate)
• Bandage the tail
• NSAIDS (Phenylbutazone or flunixin) & Antibiotics
• Aseptic preparation of the scrotum
• Infiltration of local anaesthesia – cord and surgical incision site
• Repeat scrub of scrotum

Question 10

Describe the steps to prepare for field anaesthesia castration

Answer 10

• Various anaesthetic combinations
• IV catheter
• Lateral recumbency
• Elevation of upper hindlimb
• Castrate lower testicle first so blood runs away from the surgical site

Question 11

Which piece of equipment is used for castration, how is it used correctly?

Answer 11

Serra Emasculators – have a part that cuts and another that crushes
Nut to nut!

Question 12

What are open vs closed castrations?

Answer 12

Open = vaginal tunic entered
Closed = vaginal tunic NOT entered (often involves placing ligature but not always)

Question 13

Describe the post-op care following castration

Answer 13

Check tetanus status
Antibiotics and NSAIDs
Box rest for 24hrs followed by controlled exercise
Keep away from mares

Question 14

Following castration when should owners be advised to contact the practice?

Answer 14

Contact the practice if:
- Dripping from the incisions persists > 4hrs or if there is a steady stream of haemorrhage
- Evidence of tissue hanging from the incision
- Marked swelling of the scrotum / stiffness that persists >3 days
- Depression, inappetence or colic

Question 15

List the potential complications that can occur following castration

Answer 15

Swelling
Haemorrhage
Evisceration
Omental prolapse
Septic funiculitis
Clostridial infection
Septic peritonitis
Penile damage
Hydrocele
Continued masculine behaviour
Incomplete cryptorchid castration

Question 16

What is a rig?

Answer 16

Cryptorchid male

Question 17

What is cryptorchidism?

Answer 17

Retention of one testis / both testes along the normal path of descent
Terminology: Complete, Incomplete or Inguinal

Question 18

How can cryptorchidism be diagnosed on history and clinical exam?

Answer 18

Behaviour
Previous surgery – has someone else previously attempted castration?
Thorough external palpation:
- Sedation
- Are any testicular structures palpable & on which side?
- Are any castration scars palpable?

Question 19

How is hormone analysis used to diagnose cryptorchidism?

Answer 19

• Horses < 2 y.o. & donkeys of any age - hCG stimulation test
• Horses ≥ 3 y.o. – oestrone sulphate assay
• Anti-Müllerian Hormone (AMH): Granulosa cell tumours and cryptorchids

Question 20

Describe cryptorchid castration

Answer 20

Always open tunic to ensure the whole testicle is removed
Always remove cryptorchid testicle first
Laparoscopy

Question 21

Describe direct vs indirect inguinal herniation

Answer 21

Direct = trauma/hole made in the body wall and then gut comes out of this hole
Indirect = hole that is there anyway e.g. inguinal ring, and gut comes out of this hole

Question 22

When is surgery for inguinal hernias indicated?

Answer 22

Increasing in size
Strangulating (non-reducible)

Question 23

Strangulating hernia should be considered in all stallions / colts that present with which condition?

Answer 23

Colic

Question 24

What is the most common type of penile and preputial neoplasia?

Answer 24

Squamous cell carcinoma

Question 25

How is penile and preputial neoplasia diagnosed?

Answer 25

History & presenting signs
Visual appearance: Proliferative, Ulcerative
+/- biopsy

Question 26

How is penile and preputial neoplasia treated?

Answer 26

1. Medical therapy:
   - Cryotherapy
   - Topical chemotherapeutic agents
2. Surgery:
   - Local excision
   - Reefing
   - Partial or en bloc phallectomy
3. Euthanasia - Suspected metastatic spread
4. Distal Phallectomy (Penile Amputation)

Question 27

How can penile neoplasia be prevented?

Answer 27

Owner education – cleaning sheath regularly (smegma = carcinogenic)
Examination of the penis as part of routine yearly check-up in older geldings

Question 28

How is penile trauma treated?

Answer 28

Ice packs / cold hosing
NSAIDs & Antibiotics
+/- referral
Provide support to the penis
Suture penis within sheath with umbilical tape

Question 29

What is priapism?

Answer 29

Persistent erection without sexual excitement

Question 30

Priapism can occur as a consequence of the administration of which drug?

Answer 30

Acepromazine

Question 31

How is priapism treated?

Answer 31

IV clenbuterol
Intra-CCP phenylephrine
Lavage CCP

Question 32

What is paraphimosis?

Answer 32

Inability to retract the penis into the prepuce
If prolonged can lead to pudendal nerve injury

Question 33

How is paraphimosis treated?

Answer 33

Support /suture in prepuce with umbilical tape
NSAIDs
Massage

Question 34

What is phimosis?

Answer 34

Inability to protrude the penis
Urinate in their sheath
Treat surgically