Surgical contraception Flashcards
In what species is female surgical neutering commonly done?
bitch
queen
rabbit
rodents
guinea pigs
Why is female surgical neutering not common in ferrets?
due to risk of hyperadrenocorticism and relative success of using off-license depot GnRH agonist
What are the different methods of surgical contraception in females?
ovariohysterectomy - removal of the ovaries and uterus
Ovariectomy - removal of the ovaries
Hysterectomy - removal of the uterus
What is the outcome of a ovariohysterectomy?
Elimination of oestrus behaviour and inconvenience
Prevention of pregnancy
Protection against mammary / ovarian / uterine disease
May increase risk of other diseases (some neoplasia and urinary incontinence)
What is the outcome of an ovariectomy?
Elimination of oestrus behaviour and inconvenience
Prevention of pregnancy
Protection against mammary / ovarian / uterine disease
May increase risk of other diseases (some neoplasia and urinary incontinence)
What is the outcome of a hysterectomy
Oestrus behaviour and inconvenience continues
Prevention of pregnancy
Protection of uterine disease
No increase risk of other diseases
If the uterus if not removed during surgical contraception it should not result in uterine disease unless…?
- the uterus was already abnormal
- you leave an ovarian remnant
- exogenous reproductive steroids are administered
- there is a neoplasm producing reproductive steroids (e.g. adrenal - possible but rare)
What are the advantages of removing the ovaries?
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
What are the disadvantages of removing the ovaries?
Increased incidence of some neoplasia (osteosarcoma, haemoagiosarcoma)
Increased incidence of urinary incontinence in dogs
Changes in coat texture
Tendency to gain weight
Changes in behaviour
What are the advantages of a pre-pubertal neuter?
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
What are the disadvantages of a pre-pubertal neuter?
- 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
- increased risk of some neoplasias
When is neutering in the bitch recommended?
Most common: At least 12 weeks after first oestrus (anoestrus period)
- Spaying before 12w can lead to pseudopregnancy
Avoid neutering during oestrus (increased vascularity)
Spaying too early may increase long-term disease risks
How does timing of neutering affect the risk of pseudopregnancy in the bitch?
Spaying in luteal phase (Day 30-70) causes sharp progesterone drop → increasing prolactin → iatrogenic pseudopregnancy
Spaying in anoestrus avoids this issue
If pseudopregnancy occurs, treat with prolactin inhibitors
What is the effect is spaying at this time in the bitch?
Spaying in luteal phase (Day 30-70) causes sharp progesterone drop → increasing prolactin → iatrogenic pseudopregnancy
What is the effect is spaying at this time in the bitch?
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
When should neutering be done in the queen?
oestrus should be avoided as the tract is more vascular and friable
What are the methods of surgical neutering in the male?
Orchiectomy (orchidectomy or castration)
Vasectomy (mainly teaser rams)
Crushing of spermatic cord (calves)
Inducing ischaemic necrosis of scrotum (lambs)
Injection of irritants into testis (feral dogs some countries)
What are the indication of surgical neutering in the male?
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)
What are the different techniques of castration?
Open
Closed
Modified (open then closed)
Refers to the parietal vaginal tunic
Label these testicular structures
Describe the different ways a horse may anaesthetised for castration and which method would be used
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
Describe the process of an open castration in the horse
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
How is a closed castration in the horse performed?
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 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
Describe the modified open castration procedure in horses
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
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
