Surgery of the stallion reproductive tract Flashcards
Indications for castration of a stallion
- Reduce masculine behaviour/easier mgt
- Control breeding
- Inguinal hernia
- Testicula trauma/torsion
- Testicular pathology (neoplasia etc.)
What methods of castration of horses are available?
Risks of each?
Surgical castration - high complication rate
Immunological castration (GnRH vax = Equity)
- unknown effect on future fertility
- banned in racing/equestrian horses
What pre-procedure planning/checks must be performed before commencing surgical castration of a stallion?
ID the horse
Obtain client consent
Hx + general PE
Inspect scrotum - both testes descended/inguinal hernia
Up-to-date tetanus vax?
± prophylactic AB (penicillin + gentamycin)
What mitigating factors might be present which may indicate the use of prophylactic ABs for Sx?
Surgical duration > 90 mins
Sx involving an implant
Sx-site infection would be a life-threatening challenge to patient
Benefits/disadvantages of standing castration of a horse
Indications for standing castration
Cost advantage
Higher complication rate
Indications = quiet colts whose testes can be palpated w/o sedation
What anaesthetic method is used for a standing castration of a horse?
Sedation
Nose twitch applied
Local Ax into each scrotal flask + into each testis + into spermatic cord
Ax protocol for castration under GA
Short IV Ax = ACP/xylazine + diaz/opioids/ketamine
Prolonged procedures (cryptorchid) = gas/TIVA
LA into testes + spermatic cord
What surgical techniques can be used for equine castration?
Open = parietal tunic incised + left open (no ligation at all)
Closed = parietal tunic is ligated w/o incision
Semi-closed = parietal tunic is incisd + inside structures are ligated, then tunic later closed
What techniques may be employed to minimise complications during castration Sx?
Good asepsis
Long skin incisions to allow post-op drainage
Adequate removal of tunic
Good haemostasis
Diagrams of testicular structures seen in open + closed techniques
Which castration technique (open/closed/semiclosed) is generally used for standing castration?
Outline the protocol
Open technique (as harder to maintain asterility TF ligatures are difficult to place)
Open scrotum + exteriorise testis
Incise parietal tunic + peel back (ensure no remnants)
Use emasculator to crush spermatic cord (testicular a./v./n.)
Leave open for good drainage
What castration techniques can be used for sx under GA?
What considerations must be considered?
Any technique - open/closed/semi-closed
- closed technique = lowest complication rate but requires most care
Considerations:
- Degree of asepsis attained
- Ligation of cord vs emasculation only
- Close tunic?
- Close skin - only if in operating theatre, not in-field
General protocol for in-field castration under GA
- Pre-op prep
- Op technique
- Post-op care
Pre-op:
- Short GA - triple-drip TIVA (xyl/diaz/ket = 15-20min)
- Tetanus prophylaxis + PBZ ± ABs
- IV catheter
- Position = lateral or dorsal recumbency
- Sterile equipment
- No clipping needed - only wide surgical scrub of area ± drapes
Op technique:
- Grasp testis from cranial aspect → longitudinal skin incision in ventral scrotum (parallel to midline raphae)
- Exteriorise testis w/in parietal tunic
- Closed technique = emasculate cord w/o incising parietal tunic
- Open technique = bluntly incise parietal tunic
- apply haemostasis to cord (proximal to emasculation site)
- grasp + cut the attachment of the tunic to the tail of the epididymis
- emasculate cord - 2-3mins for good haemostasis
- cut off + discard testis
- ± ligate cord as additional haemostasis (monofil abs.)
- Allow cord to slide w/in the tunic to w/in inguinal canal
- Strip tunic from surrounding tissue (cremaster m.) to allow emasculation
- ± place ligature near external inguinal ring (if aseptic technique)
- Ligature around tunic = closure
- Trim any tissue which may prolapse out of wounds
Post-op care:
- Initial confinement (24hrs) then exercise
- exercise = good drainage and reduces oedema
- PBZ (3-4d)
- ± ABs
- Clean environment
- Separate from mares for few days
Diagnosis of cryptorchids
Palpate scrotum + inguinal areas
Rectal palpation of internal inguinal rings
External + rectal US (locates testis)
Laparoscopy
Endcrinological tests (if male behaviour + can’t find evidence of remnant testes):
- AMH assay (≥18mo old)
- Oestrone sulfate (≥3yo)
- hCG stim test (<2yo/donkey of any age)
Eg’s of complications of castration
Excessive haemorrhage (normal = a few drips for ≤1hr post-Sx)
Evisceration = omental/intestinal hernation through incisions
Swelling of prepuce/scrotum
Failure to remove the testis
Laceration of the base of the penis
