Surgical Contraception

Question 1

In what species are females surgically neutered

Answer 1

Bitches and Queens
Common in rabbits- esp. as best kept in male/female pair
Sometimes rodents and guinea pigs
less common in ferrets
rarely in mares due to alleged poor behaviour
Unilateral ovariectomy performed in many species in case of ovarian pathology

Question 2

Why isn’t surgical neutering commonly performed in female ferrets (jill)

Answer 2

risk of hyperadrenocorticism and relative success of using off-license depot GnRH agonist

Question 3

Advantages/ Disadvantages of Ovarioectomy

Answer 3

Elimination of oestrus behaviour and inconvenience
Prevention of pregnancy
Protection against mammary / ovarian / uterine disease (unless uterus abnormal or exogenous hormones subsequently given)
May increase risk of other diseases (some neoplasia and urinary incontinence)

Question 4

Advantages/ Disadvantages of hysterectomy

Answer 4

Oestrus behaviour and inconvenience continues
Prevention of pregnancy
Protection of uterine disease
No increase risk of other diseases

Question 5

In what cases would leaving the uterus in result in uterine disease

Answer 5

the uterus was already abnormal
you leave an ovarian remnant
exogenous reproductive steroids are administered
- Reasons for administration of reproductive steroids would include
-Oestrogens for urinary incontinence
there is a neoplasm producing reproductive steroids (e.g. adrenal - possible but rare)

Question 6

What is current best practice for female neutering

Answer 6

Post-pubertal (laparoscopic) ovariectomy

Question 7

What happens when you spay in anoestrus

Answer 7

GOOD GRAPHS ON NOTES
Normal progesterone and prolactin profiles in a non-pregnant dog.
Luteal phase 70d
Spaying after d70 (commonly its left until 3m) but before the onset of the next proestrus is the common time for surgery

Question 8

What happens when you spay in Luteal Phase (30 days after oestrus) in bitch

Answer 8

Removal of the ovaries after day 30 causes a dramatic decrease in progesterone which stimulates an increase in prolactin and causes an iatrogenic pseudopregnancy.
These cases generally don’t resolve spontaneously and require administration of prolactin inhibitors

Question 9

What happens if you spay in luteal phase (21 days after oestrus)

Answer 9

Removal of the ovaries before prolactin is ‘turned on’ results in a fall of progesterone but no increase in prolactin and so pseudopregnancy is not induced

Question 10

When would you perform a vasectomy

Answer 10

Mainly in teaser rams, to detect which ewes are in oestrus

Question 11

When might you inject irritant to testis to neuter a dog

Answer 11

Feral dogs in some countries

Question 12

4 indications for surgical neutering in male

Answer 12

Elimination or reduction of male-like behaviour
Prevention of breeding
Treatment of conditions affecting the testes and scrotum
Treatment of conditions stimulated by male hormones (e.g. prostate disease / anal adenomata in dogs)

Question 12

3 different castration techniques

Answer 12

Open
Closed
Modified (opened then subsequently closed
*Refers to the parietal vaginal tunic

Question 13

3 types of anaesthesia used for castration of the horse

Answer 13

May be conducted standing with sedation, twitch and local anaesthesia
Usually open castration

May be conducted under general anaesthesia in the field
Usually closed castration

May be conducted under general anaesthesia in the theatre
Usually modified technique

Question 14

5 things to think about in pre-operative evaluation of horse for castration

Answer 14

Physical examination
Palpation of scrotum and inguinal canal
Suitability for anaesthesia

Tetanus prophylaxis in stallion (also goat)

Pre-operative antimicrobial preparations
Pre-operative analgesia

Question 15

Open castration in horse procedure

Answer 15

Testis is tensed
A 8-10 cm skin incision in scrotum is made 2-3 cm from median raphe
Incision carried through skin and muscle
The vaginal tunic is opened and testes pushed out
Fascia is stripped away using a dry gauze
The cord is emasculated either as one portion or two (vascular and vas)
An absorbable ligature may or may not be applied
The remnant tunic is also emasculated
The tunic, sub-cutaneous tissue and skin are left open

Question 16

Closed castration in horse

Answer 16

As for ‘open’ technique but the vaginal tunic is not opened
The subcutaneous tissue is pushed back with a dry swab
Transfixing sutures are normally placed through the tunic anchoring the vascular portion, and then applied circumferentially around the whole cord compressing the vas
The cord is emasculated as a whole
The skin is normally left open

Question 17

Modified Castration in Horse

Answer 17

The procedure is performed as for an ‘open’ castration
Rather then removing the tunic, it is twisted along its long axis, transfixed and then emasculated
The sub-cutaneous tissue may or may not be sutured closed
Skin may or may not be closed

Question 18

Open v closed v modified castration in horse

Answer 18

Open
Rapid, effective observation of vasculature, allows good drainage, may be useful when conditions likely to be contaminated, herniation risk increased

Closed
Rapid, does not allow observation of vasculature but effective haemostasis if surgical field controlled, peritoneal contamination minimised, herniation risk reduced

Modified (open then subsequently closed)
More time consuming, allows good haemostasis and surgical closure but only if surgical conditions are guaranteed clean, herniation risk reduced

Question 19

Ways to castrate a dog

Answer 19

Surgical technique under general anaesthesia
– usually a single mid-line incision but surgeon preference.

Commonly performed as:

Modified (open then subsequently closed)

Closed – more often in smaller dogs

Open (but skin closed unlike horse where skin left open for drainage)

Question 20

Best time for male dogs to be castrated

Answer 20

Post-pubertal- after 12 months of age

Question 21

Why don’t you clip the scrotal hair for castration

Answer 21

any razor burn caused will mean the dog licks at the area

Question 22

Techniques for tom cat castration

Answer 22

Open following twisting and traction
Open following ligation
Open following auto-ligation

Skin left open

Effect of age of castration is poorly studied but likely to be similar to dog

Question 23

Ways to castrate calf

Answer 23

Bloodless technique

Elastration in first 7 days
Induces ischaemic necrosis, care for flies and tetanus

Crushing (Burdizzo)
Pull testes down, push cord to side, apply to one cord to level of raphe, then other cord at different level

Question 24

After what age must calves/bulls be castrated by a veterinary surgeon and how would this be done

Answer 24

2 months

Local anaesthesia essential, sedation helpful
Nearly always by Open Technique
Consider:
Age and size
Time of year
Clean environment
Antibiotics
Exercise

Open Technique by either
Lateral incisions into each scrotum
Scalpel (watch the saphenous vein! and watch your wrist)
Newberry knife
Removal of the distal scrotum

Emasculators used often without ligation

Question 25

What is a newbury knife

Answer 25

used to make controlled incision in to bull/calf testes for open castration

Question 26

How are lambs castrated and when

Answer 26

‘Bloodless techniques’
Elastration in first 7 days
Crushing (Burdizzo) in first 7 days

Surgical castration is rarely performed

Question 27

How are pigs castrated

Answer 27

Surgical castration
Open technique with sharp dissection or torsion and traction
Usually no ligature or emasculation

Question 28

How are rodents castrated

Answer 28

Closed castration or Modified technique is essential
Rodents have an open inguinal canal and there is a significant risk of hernia

Careful protection of the wound using subcuticular sutures and Elizabethan collar