Neutering surgery Flashcards
Why do we neuter small animals?
- prevent breeding (population control)
- control behaviour / behavioural problems
- prevent dz (e.g. neoplasia, pyo, etc)
What happens after neutering?
- sudden drops in levels of testosterone/oestrogen
- low testosterone/oestrogen stimulates GnRH from hypothalamus
- triggers the release of luteinising hormone (LH) from pituitary
- LH levels remain high as there is no negative feedback from testosterone/oestrogen production
- LH receptors found in UT and prostate, vascular endothelium and smooth muscle in heart and spleen, skin, lymphoid tissue, GIT, pancreas, thyroid, head of femur, CCL, CNS and hippocampus, hypothalamus
What happens after neutering in females?
Pros: prevents…
- pyometra
- neoplasia (mammary, ovary, uterus)
- oestrus
- puppies/kittens
Cons:
- urinary incontinence
- hair coat changes
- obesity
- neoplasia
- immune-mediated dz
- joint dz
What happens after neutering in males?
Pros
- reduce roaming
- reduce aggression
- prevent BPH
- prevent perianal adenoma
- no testicular neoplasia
- decrease histiocytic TVT
Cons
- prostatic carcinoma
- increase aggression
- urinary incontinence
- hair coat
- obesity
- neoplasia
- joint dz
Procedures - female
- ovariohysterectomy (spay)
- ovariectomy (spay)
- ovariectomy with subtotal hysterectomy
- hysterectomy
- fallopian tube ligation
- midline
- flank
- laparoscopic
- laparoscopic-assisted
- ‘keyhole’
Controversy regarding spaying bitches
There is no medical need to remove the uterus if it is healthy
- long-term data shows no pyometra in bitches or queens following ovariectomy ± partial hysterectomy … as long as the pt doesn’t receive any exogenous progesterone
Flank vs midline
Indications for flank
- enlarged mammary gland due to lactation
- mammary gland hyperplasia
Advantages of flank
- evisceration is less likely if the body wall incision breaks down
- ability to observe incision from a distance
Contraindications
- pregnancy
- pyometra
- oestrus
- obesity
- pt age younger than 12w
Disadvantages
- limited exposure to the pts contralateral side if complications arise
- difficulty identifying a previous OHE if the animal is not properly marked
- possible imperfections in hair colour or regrowth on the flank
Surgical complications in females
- dogs 19%
- cats 12%
- incisional inflammation most common
- some complications are life-threatening
- complication rate is related to body weight and surgical time
- wound complications
- haemorrhage
- residual ovarian tissue
- stump or pedicle granulomas
- stump pyometra
- swab retention
- uterus entrapment
Wound complications
- suture reaction
- wound infection
- wound dehiscence
– skin
– linea alba (hernia)
– both -> evisceration
Surgical complications in females - why might they happen?
- most complications arise because of, or are made worse by inadequate exposure
Surgical complications in females - haemorrhage - why might it happen, what to do?
- ovarian arteries
- uterine arteries
- coagulopathy (von Willebrand)
Need to:
- increase exposure
- use suction
- convert flank to midline approach
- stay calm, try not to panic
- ask for assistance
- use mesenteric dam manoeuvres to look at ovarian pedicles
- retract bladder caudally to look at cervical stump
Surgical complications in females - residual ovarian tissue (ovarian remnant syndrome) - why might it happen, what to do?
- continued cycling activity
- more common after ‘routine’ OHE
- hormonal investigations
- R more common than L(?)
- CT scan (usefulness of US dependent on user)
- may be easier to find residual tissue when in oestrus
- may see enlarged ovarian vessels on affected site
- submit tissue for histopathology
- always open ovarian bursa after sx to check whole ovary has been removed
Surgical complications in females - uterine stump granuloma - why might it happen, what to do?
- signs consistent with infection (e.g. pyrexia, lethargic, etc)
- vaginal discharge (often blood, O might mistake for being in season)
- attractive to male dogs
- neutrophilia with left shit
- (?) vaginal swab
- abdominal US
- vaginoscopy
To resolve:
- further surgical intervention will be required, most commonly associated with pyogranulomatous response in association with suture material (catgut)
- also in most cases, a course of broad spectrum antibiotics
Surgical complications in females - sinus tract / discharging sinus - why might it happen, what to do?
Soft, painful swelling with or without discharging beneath the skin of:
- flank (ovarian pedicle ligature)
- inguinal region, medial thigh, pre-crural region (cervical ligature)
Suture material
- permanent, braided (nylon)
- catgut
Swab
- gossypiboma
- textiloma
Surgical complications in females - ureteral entrapment - why might it happen, what to do?
- uncommon (?)
- crush injury vs ligation vs transection
- azotaemia (?)
- uroabdomen (transection) (?)
- serum biochemistry analysis including electrolytes
- abdominal US
- abdominocentesis, fluid analysis
- CT scan
To fix
- ventral midline coeliotomy
- nephrectomy (?)
- re-implantation of ureter into the bladder (?)
Procedures in the male
Castration
- bilateral
- unilateral
- vasectomy
- open
- closed
- semi-open
- semi-closed
- laparoscopic
Surgical complications in males
- wound complications
- haemorrhage
- scrotal haematoma
