Surgical Contraception in Females

Question 1

What species is neutering performed in females?

Answer 1

• Commonly performed in bitches and queens
• Not uncommon in rabbits
• Sometimes performed in rodents and guinea pigs
• Less common in ferrets
  ○ Risk of hyperadrenocorticism
  ○ Relative success of using off license depot GnRH agonist

Performed in other species for ovarian pathology (unilateral ovariectomy)

Question 2

Methods of Sterilisation

Answer 2

Ovariohysterectomy
Ovariectomy
Hysterectomy

Question 3

Ovariohysterectomy

Answer 3

Removal of Uterus and Ovaries

Question 4

Benefits of overiohysterectomy

Answer 4

○ Elimination of oestrus behaviour and inconvenience
○ Prevention of pregnancy
○ Protection against mammary / ovarian / uterine disease

Question 5

Risks of ovariohysterectomy

Answer 5

○ May increase risk of other diseases (some neoplasia and urinary incontinence
○ Increased risk of haemangiosarcomas and osteosarcomas
* Particularly if early neutering

Question 6

Ovariectomy

Answer 6

Removal of the ovaries
Becoming more common in general practice
Leaves uterus behind

Question 7

Benefits of Ovariectomy

Answer 7

○ Elimination of oestrus behaviour and inconvenience
○ Prevention of pregnancy
○ Protection against mammary / ovarian / uterine disease
○ Reduction in the incidence of mammary neoplasia
○ Prevention of uterine disease including CEH, pyometra and uterine neoplasia
○ Prevention of ovarian disease including neoplasia
○ Prevention of pseudopregnancy

Question 8

Risks of ovariectomy

Answer 8

• Increased incidence of some neoplasia (osteosarcoma, haemoagiosarcoma)
  In some breeds there is a clear relation the longer that ovaries or testes are present the lower this risk
• Increased incidence of urinary incontinence in dogs?
• Changes in coat texture?
• Tendency to gain weight?
• Changes in behaviour?

Question 9

Hysterectomy

Answer 9

Removal of Uterus

Question 10

Benefits of hysterectomy

Answer 10

○ Prevention of pregnancy
○ Protection of uterine disease
○ No increase risk of other diseases
* No increased risk of neoplasia

Question 11

Risks of Hysterectomy

Answer 11

• Oestrus behaviour and inconvenience continues

Question 12

Benefits of pre-pubertal neutering

Answer 12

○ No possibility of mating at first oestrus
○ No possibility of pseudopregnancy
○ Surgical procedure easier therefore more rapid (often ovariectomy performed)
○ Reduced anaesthetic time, rapid recovery etc.
○ Less urinary incontinence?

Question 13

Disadvantages of pre-pubertal neutering

Answer 13

○ Smaller animal with fewer fat reserves (greater potential for anaesthetic overdose)
○ Delayed closure of growth plates (increased risk of physeal fractures)
○ Persistence of pre-pubertal vaginitis if present before neuter
○ Subsequent underdevelopment of the sexual organs
○ ? Worsened post-spay incontinence
○ ? Persistence of puppy coat
○ ? Underdeveloped behavioural characteristics
○ ? Tendency for worse obesity

Question 14

When should you spay a bitch?

Answer 14

Preferably >12 weeks after oestrus

Question 15

What happens if you spay in luteal phase?

Answer 15

Causes dramatic decrease in progesterone
This stimulates increase in prolactin from PTH
Iatrogenic pseudopregnancy

Question 16

What happens if you spay in early luteal phase

Answer 16

Must be before prolactin production (before week 3)
No induction of iatrogenic pregnancy

Question 17

When to spay a cycling queen