Spay and castrations

• Why do we neuter small animals?

  Prevent breeding (population control)

  Control behaviour/ behavioural problems e.g. urine spraying in cats.

  Prevent disease.
• What happens after neutering?

  Sudden drop in levels of testosterone/oestrogen.

  Low testosterone or oestrogen stimulates GnRH from hypothalamus.

  Triggers the release of Leyte using hormone (LH) from pituitary.

  LH levels remain high as there is no negative feedback from testosterone/oestrogen production.

  LH receptors foin 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 are the pros of neutering females?

  No pyometras

  No neoplasia of the mammary gland and related reproductive organs.

  THe animals stops having to go through oestrus.

  Control of population.
• What are the cons of neutering females?

  Urinary incontinence (more common in settlers which may influence decision making).

  Can cause changes in hair coat.

  Obesity

  Neoplasia

  Immune mediated disease

  Joint disease.
• What are the pros of neutering males?

  Reduced roaming.

  Reduce aggression (but not always)

  Prevent BPH

  Prevent perianal fistula

  No testicular neoplasia

  Decrease in histiocytic TVT.
• What are the cons of neutering males?

  Prostatic carcinoma (incidence is low and is less significant than prostatitis which has a higher incidence and occurs in entire dogs).

  Increase in aggression.

  Urinary incontinence.

  Hair coat

  Obesity

  Neoplasia

  Joint disease.
• What are the procedure options for neutering females?

  Ovariohysterectomy (spay/spey)

  Ovariectomy (spay/spey)

  Ovariectomy with subtotal hysterectomy (occurs in cats when you can not fully reach the cervix with the flank approach).

  Hysterectomy - uncommon in the UK

  Fallopian tube ligation - uncommon in the UK.
• Regional anatomy - female

  In some individuals the suspensory ligament needs to be broken down, this is tighter in the bitch than the cat.

  • It is more lax in an alder bitch, gravid bitch or one with a pyometra.
• Why do an ovariectomy?

  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 patient does not receive any exogenous progesterone.
• Flank vs midline - indications and advantages for flank

  Indications:

  • Enlarged mammary gland due to lactation.
  • Mammary gland hyperplasia.

  Advantages:

  • Evisceration is less likely f the body wall incision breaks down.
  • Ability to observe incision from a distance.
• Flank vs midline - contraindications and disadvantages

  Contraindications:

  • Pregnancy
  • Pyometra
  • Oestrus
  • Obesity
  • Patient age younger than 12 weeks

  Disadvantages:

  • Limited exposure to the patients contralateral side if complications arise.
  • Difficulty identifying a previous OHE if the animal is not properly marked.
  • Possible imperfections in hair colour or re growth on the flank (especially in colour point animals e.g. Siamese).
• What are the surgical complications?

  Incisional inflammation is the most common.

  Wound complications

  Haemorrhage

  Residual ovarian tissue

  Stump or pedicle granulomas

  Stump pyometra

  Swab retention

  Ureteral entrapment
• Surgical complications - wound complications

  Suture reaction

  Wound infections

  Wound dehiscence

  • Skin
  • Linea alba (hernia into the subcutaneous space)
  • Both => evisceration (which the animal may attempt to eat).
  • These often have bad outcomes with a high infection risk and the potential need to resect some of the intestines.
• Why do surgical complications occur?

  Most complications arise because of, or are made worse by inadequate exposure.
• Surgical complications - haemorrhage

  Ovarian arteries

  Uterine arteries

  Coagulopathy (von Willebrand)

  • At least do a buccal bleeding test in breeds that are susceptible.
  • Definitely test if an owner mentions a bleeding issue.
• Surgical complications - residual ovarian tissue

  Continued cycling activity

  More common after ‘routine’ OHE.

  Hormonal investigations.

  Right is more common than left.

  Might be easier to find residual tissue when in oestrus.

  May see enlarged ovarian vessels on affected side.

  Submit tissues for histopathology.
• Uterine stump granuloma

  This is used interchangeably with a stump pyometra, but they are different, a granuloma occurs to suture material and is more common.

  Signs consistent with infection (e.g. pyrexia, lethargic).

  Vaginal discharge (often bloody - owner might mistake for being in season).

  To resolve condition further surgical intervention will be required - most commonly associated with pyogranulomatous response in associates with suture material (catgut).
• Surgical complications - sinus tract/ discharging

  Soft, painful swelling with or without discharging beneath the skin of:

  • Flank (ovarian pedicle ligature).
  • Inguinal region, medial thigh, pre-crural region (cervical ligature).

  Causes include:

  • Suture material:
  • Permanent, braided (nylon)
  • Catgut.
  • Swab (gossypiboma, textiloma) left in.
• Surgical complications - ureteral entrapment

  Uncommon.

  Crush injury vs ligation vs transection.

  Can cause azotaemia and uroabdomen.

  Serum biochemistry analysis including electrolytes.

  Abdominal ultrasonography.
• What are the procedure options for neutering the male?

  Castration - open

  • Bilateral - closed
  • Unilateral - semi-open
  • Vasectomy - semi-closed
• What are the surgical complications in neutering the male?

  Wound complications

  Haemorrhage

  Scrotal haematoma.
• Surgical complications - scrotal haematoma

  Can look like they are not neutered.

  Scrotal ablation may be needed in some cases