Neutering of Male Dogs and Cats

Question 1

1. Define orchiectomy.
2. Define cryptorchidectomy.
3. Define vasectomy.
4. Define scrotal ablation.
5. Medical option for male desexing.

Answer 1

1. Removal of the testicles.
2. Removal of testicle(s) that haven’t descended into the scrotum.
3. Removal of a portion of the vas deferens.
4. Removal of scrotal skin (normally performed alongside orchiectomy).
5. Temporary chemical castration e.g. by use of a Suprelorin (Deslorelin).
   - Licensed in dogs, cats and ferrets.
   – Mainly used to trial effects of castration (e.g. behavioural), or if O’s wish to breed later.

Question 2

Reasons for castration.

Answer 2

• Population control (esp. cats).
• Management/behavioural modification.
• Infectious disease control.
  – FIV, TVT (Transmissible Venereal Tumour).
• Compliance w/ legal requirements (XL bully legislation).
• Prevention/treatment of disease.
  – Testicular disease, perineal rupture, perianal adenoma, prostatic diseases.
• Control of hereditary diseases.

Question 3

Possible adverse effects of castration.

Answer 3

• Weight gain due to increased appetite and decreased activity (reduce calorie intake post-castration).
• Behavioural – nervous dogs may worsen (work w/ behaviourist first, consider temporary chemical castration trial).
• Increased risk of bladder and prostate cancer – rare.
• Delayed closure of growth plates w/ early neutering – esp. giant breeds.

Question 4

Possible surgical complications of castration?

Answer 4

• Scrotal bruising/swelling.
  – Importance of gentle tissue handling.
• Haemorrhage.
  – Scrotal haematoma.
  – Haemoabdomen (ligature failure).
• Infection and wound dehiscence.
  – Self trauma.
  – BUSTER COLLARS IMPORTANT!

Question 5

Timing of surgical castration.

Answer 5

• Dogs = 6-9m but now common to consider waiting longer esp. w/ bigger breeds.
• Cats = 4-6m but can be done earlier, from 8wks but increased GA risk.

Question 6

1. Open castration.
2. Closed castration.
3. How to decide between open and closed castration.

Answer 6

1. Incise and peel away vaginal tunic, ligatures placed around exposed blood vessels and vas deferens.
2. Tunic left intact, ligatures placed around outside of tunic (incorporating more tissue.
3. • Closed is simpler, reduced risk of peritoneal contamination or herniation.
     - Closed for testicular tumours.
     - Open allows more secure ligatures which can be preferable for larger dogs.
     - Personal preference.

Question 7

Dog castration preparation.

Answer 7

• Dorsal recumbency.
• Single skin incision: midline, pre-scrotal.
• Avoid clipping too close on scrotum as skin is sensitive – BEWARE RASH!
• Intratesticular LA injection.
• Aseptic preparation and drape to cover scrotum and penis.

Question 8

Dog castration step-by-step (first part of any dog castrate).

Answer 8

• Push testicle cranially out of scrotum, hold firmly in ‘claw grip’ and incise skin over top of testicle.
• Incise through fascia.
• Push testicle through skin incision.

Question 9

1. What is the most important reason to push up testicle and make skin incision directly on top of testicle?

Answer 9

1. Avoid accidentally cutting too deep and damaging structures under pre-scrotal skin.

Question 10

Next step-by-step for open dog castrate?

Answer 10

• Incise through vaginal tunic and control depth not to cut into testicle itself.
• Break down ligament of epididymis (where vaginal tunic attaches), using haemostat/swab.
• Fully exteriorise testicle by applying caudal and outward traction.

Question 11

Next step-by-step for closed dog castrate.

Answer 11

• Break down external fascia and fat using haemostat/swab.
• Fully exteriorise testicle by applying caudal and outward traction.

Question 12

Next step-by-step (all dog castrates).

Answer 12

• Apply 4 artery forceps to spermatic cord.
• Tie 2 ligatures in the crush of the most proximal haemostats.
• Ensure ligature secure.
  – synthetic absorbable suture material, approx. 2-0 or 3-0 (2 or 3 M) dept. on size of dog. (monofilament, e.g. PDS, for constricting knots, or multifilament, e.g. Vicryl, for surgeon’s knot.

Question 13

Next step-by-step for all dog castrates.

Answer 13

• Cut between 2 most proximal clamps w/ blade or scissors.
• Check ligated cord not bleeding before releasing it.
• For open, consider closing or ligating tunic.
• Repeat for second testicle, pushing it up through the already made skin incision.

Question 14

Next step-by-step – closure (all dog castrates).

Answer 14

• Suture SC tissue w/ simple continuous pattern + synthetic absorbable suture material e.g. monocryl.
• Suture skin closed w/ intradermal pattern (less irritant) or external cruciate sutures (cheaper).
  – synthetic monofilament e.g. monocryl for intradermals.
  – non-absorbable e.g. nylon for ext. cruciate sutures.
  – on a cutting or reverse cutting needle.

Question 15

Cat castration preparation.

Answer 15

• Lateral recumbency.
• Clip or pluck scrotum (clip less traumatic).
• Intratesticular LA injection.
• 2 possible techniques:
  – open –> separate cord and vessels and tie (common); or ligate (unusual).
  – closed –> using haemostats.

Question 16

Cat castration technique (open).

Answer 16

• Incise over testicle w/ scalpel blade, through scrotum and vaginal tunic (keep incision parallel to the intratesticular septum/raphe).
• Break down ligament of tail of epididymis and strip fascia away from testicle.
• Break off vas deferens close to testicle to separate it from blood vessels.
• Tie vas deferens in a knot w/ blood vessels (use square knot w/ at least 4 throws). Cut testicle off w/ scalpel blade and tug the scrotum so knot returns inside.
• Repeat for second testicle.

Question 17

1. Advantage of closed cat castrate.
2. Disadvantage of closed cat castrate.

Answer 17

1. Quicker.
2. Only one throw, so less secure?
   Uses a surgical instrument so added cost of autoclaving.

Question 18

1. When are testicles normally descended by?
2. What if still not descended by 6mths.
3. Classification of location of retained testicle.

Answer 18

1. 30-40 days. If not descended by 8 weeks, then testicle ‘retained’, but can be difficult to palpate testicles in young puppies and kittens – make clinical note and wait.
2. Surgery.
3. • Pre-scrotal.
     - Inguinal.
     - Abdominal.

Question 19

1. Why must the retained testicle be removed?
2. What can you do to determine whether cryptorchid or already castrated?
3. How to locate retained testicle.
4. Owner communications regarding cryptorchid castration.

Answer 19

1. Increased risk of neoplasia (potentially 10X).
2. Test for plasma testosterone.
3. Careful palpation of inguinal region (easier under sedation/GA).
   Abdominal ultrasound.
4. Increased cost, morbidity, risk of complications compared to normal castration.

Question 20

Inguinal cryptorchid castrate surgical technique.

Answer 20

• Stabilise and incise skin over testicle.
• Ensure correctly identified testicle.
  – often smaller / softer / abnormally shaped.
• Ligate and close as normal.
  *similar to normal castration, just needs additional incision at site of retained testicle.

Question 21

Abdominal cryptorchid castrate surgical technique.

Answer 21

• Ex lap.
  – If cranially, incise ventral midline.
  If caudally, incise adjacent to prepuce.
  –> beware increased haemorrhage and morbidity. Important to locate testicle first w/ imaging.
  – Search from kidney to inguinal canal.
  – If struggling, follow vas deferens from prostate.
  – Ligate as normal.
• Laparoscopy – best option as less morbidity.

Question 22

Laparoscopic removal of abdominal cryptorchid testes.

Answer 22

• Specialist equipment and training.
  – fairly easy to learn.
• Becoming increasingly available in first-opinion practice.
• Advantages:
  – Less invasive, less morbidity/tissue trauma.
  – Less pain, faster recovery.
  – Improved visualisation.
  – Potentially quicker than ex lap dept. on operator experience.

Question 23

1. What is scrotal ablation?
2. Indications for scrotal ablation?

Answer 23

1. • Old dog w/ v pendulous scrotum – risk of trauma.
     - Testicular and/or scrotal neoplasia.
     - Trauma.
     - Treatment of haematoma / seroma / abscess following routine castration.

Question 24

Scrotal ablation technique.

Answer 24

• Incise around the base of the scrotum (skin and fascia).
• Control haemorrhage.
• Perform routine open or closed castration on the testicles.
• Break down scrotal septum that separates the 2 testicles.
• Routine closure of wound.

Question 25

1. What is the effect of a vasectomy?
2. Surgical technique for vasectomy?

Answer 25

1. Inhibits fertility but has no effect on behavioural patterns (roaming, aggression, marking) and no reduction in hormonally associated diseases.
2. • Pre-scrotal incision.
     - Incise into vaginal tunic.
     - Locate ductus deferens, ligate and resect a small segment.

Question 26

1. ABX for routine castration?
2. Regional anaesthesia for routine castration?

Answer 26

1. No indication.
2. Intra-testicular injection of LA e.g. lidocaine.
   - one injection per testicle.
   - after clip and quick initial clean, but before aseptic scrub.
   - Good multi-modal intra-operative analgesia.

Question 27

1. Post op analgesia.
2. Prevention of self-trauma at incision site.
3. Exercise restrictions.
4. POC.

Answer 27

1. Dogs = short (3-5d) course n=analgesia e.g. NSAID.
   Cats = General consensus is post op analgesia not required.
2. • Buster collar.
     - Gentle tissue handling and suturing.
3. Dogs = 10d rest, short lead walks only.
   Cats = 3d keep indoors and prevent jumping.
4. 2d cats and dogs - phone/in person.
   10d dogs (+ stitches out).