Equine urogenital surgery and castration Flashcards
Pros and cons of standing castration
Quicker and don’t have risks of general anaesthetic
But can only do an open castration
When might we choose to do a castration under GA
Mature stallions over 4 years due to increased risk of haemorrhage/herniation
History of inguinal hernia as foal
Cryptorchid
If very fractious
Donkeys
How do we castrate a foal with a hernia
closed castration and twist tunic to milk any intestines back into abdo cavity then ligate as low as possible
Pre-op preparation and analgesia for a standing castrate
Detomidine, butorphanol
Buprenorphine
Tetanus prophylaxis if needed
Antibiotics if very dirty
Prep surgical site including inner thighs
Where do we inject local anaesthetic for standing castrate and how much
5-10 mls total in the testss
Line of LA in the skin, a couple cm lateral to the midline raphe
[end up with 10-15ml per side]
Where to make incision for standing castrate
1-2 cm lateral to the midline raphe (thin dark line)
Need to keep it quite ventral to ensure good drainage and avoid seroma formation
How to place an emasculator
Nut to nut
Want wing close to testicle; this allows it to crush then cut the cord
When should we place ligatures in castration
Only if dealing with haemorrhage because this will predispoe to infection (and this is a contaminated procedure)
How much haemorrhage do we expect after a standing castrate
Dripping for 30-60 mins (such that we can count the drops i.e not a steady stream)
What are some causes of excessive haemorrhage in a standing castrate
Placing emasculator the wrong way round
Using the wrong size emasculator
NOt holding emasculator on long enough
How to deal with a bleeder in a standing castrate
Re-sedate the horse
Try and find the stump of the cord using artery forceps
Place forceps on transversely, leave for 24hrs and re-sedate to remove
(or use ligature if you can’t come back to the yard to remove forceps)
What to do with a bleeder from standing castrate if we can’t find the cord
Pack scrotal wound with long sterile bandage
IF this isn’t enough then go a quick GA, find the cord and then clamp/ligate
What are some advantages of castration under GA
CAn do a closed castration which minimises risk of evisceration, haemorrhage and better asepsis
How to perform a close castration under GA
Incise scrotum, pull out testis, strip off the tissue from the tunic
Place two transfixing ligatures around the cord using thick metric vicryl
Emasculate distal to the ligatures, nut to nut
Probably don’t worry about closing the skin
Post-op care after castrate
NSAIDs for a few days
Antibiotics if very dirty or break in sterility
Box rest for 24 hours and check regularly for haemorrhage
THEN do forced walking out to reduce the oedema
How long can stallions be fertile for after castration
1-2 months
What would we see with a surgical site infection post-castrate
Excessive oedema, purulent discharge, lameness/stiff gait, pyrexia
What are some predisposing factors for surgical site infection with castration
contamination during surgery
using ligatures in non-sterile procedure
dirty environment
too small scrotal incisions since gives poor drainage and too rapid closure to haematoma retained
Too lateral incisions as get poor drainage
Treatment for surgical site infection post-castrate
Sedate, re-establish drainage by opening the incision, clean out clots/pus, lavage using physiological saline or dilute iodine
Systemic antibiotics
What is funiculitis and how do we treat
Infection of the cord stump
Get unresolving acute infection so thickened cord stump
Rare and generally related to sutures being left in
Dissect out bluntly and transect on a clear piece of spermatic cord; avoid ligature placement
What is schirrous cord
Chronic funiculitis with granulomas on scortum and small drainage tracts
Again, related to non-absorbable suture material
What would a lace-like protrusion from a castration wound be
Omentum prolapse
Why are we not likely to get evisceration where there has been omental prolapse
Because the omenum plugs the inguinal canal
Treatment for dartos prolapse post-castration
Sedate, clean, inject LA, clamp and trim
Treatment for omentum prolapse post-castration
Sedate, pull out a bit more healthy omentum and resect using emasculators while stnading or under GA
Which individuals might be more likely to get evisceration post-castration
Draft breeds
Mature stallion
How to deal with large evisceration post-castrate in short term
Sedate horse, place damp nappy to support guts while referring to nearest emergency centre
What is a hydrocoele post-castration and when might we get it
= filling up of the scrotal sac with peritoneal fluid
= Generally after an open castrate where excess vaginal tunic has bene left in place
= non-painful and can be manually reduced bu may open and resect out tunic to solve cosmetic issue
Why might we still get stallion like behaviour post-castrate
Because this behaviour is learned not just hormonal
More common to get this in older stallions
Which breed is prone to cryptorchidism
Welsh ponies
How to tell if a ‘castrated horse’ has a retained testicle
Anti-mullerian hormone bblood test is most accurate marker of testicular tissue
Options other than anti-mullerian hormone for telling if a castrated horse has a retained testicle
Testosterone concentration pre and post-HCG stimulation
Oestrogen sulphate assay (if>3y/o)