Surgery of the equine male reproductive tract Flashcards
When do the testes drop?
- 270- 300days gestation - should be born with testes
Why would you castrate a horse?
- Prevent breeding
- Modify behaviour
- Neoplasia / inguinal hernia
What should be considered with castration?
- Age
- Breed / size
- Temperament
- Season
What should be done for pre-op assessment with castration?
- History - previous scrotal / inguinal hernia
- Good restraint essential
- Clinical exam - auscultate the heart
- Palpation of testes
What are different options for carrying out a castration?
- Standing sedation vs general anaesthesia
- Field anaesthesia vs GA under theatre conditions
How should a standing castration be carried out?
- Sedation (α2 agonist & opiate)
- Bandage the tail
- NSAIDS & Antibiotics
- Aseptic preparation of the scrotum
- Infiltration of local anaesthesia
- Repeat scrub of scrotum
- Then castrate in a similar manner to castration under GA
What needs to be done with field anaesthesia?
- Various anaesthetic combinations
- IV catheter
- Lateral recumbency
- Elevation of upper hindlimb
- Castrate lower testicle first
What do open + closed castrations refer to?
- Whether or not the vaginal tunic has been incised
What are special circumstances with castrations?
- If there are large cords - emasculate vascular + fibromuscular portions separately
- Donkeys (large inguinal rings)
- History of scrotal / inguinal hernia - ligature around vaginal tunic +/- suture superficial inguinal ring
What is aftercare of castration?
- check tetanus status
- Antibiotics
- NSAIDs
- Box rest for 24hrs - followed by controlled exercise
- Keep away from mares
When would you tell the owner to contact the vet regarding post castration?
- Dripping from the incisions persists > 4hrs or if there is a steady stream of haemorrhage
- Evidence of tissue hanging from the incision
- Marked swelling of the scrotum / stiffness that persists >3 days
- Depression, inappetence or colic
What are complications following castration?
(most common)
* Swelling
* Haemorrhage
* Evisceration
* Omental prolapse
(less common)
* Septic funiculitis
* Clostridial infection
* Septic peritonitis
* Penile damage
* Hydrocele
* Continued masculine behaviour
* Incomplete cryptorchid castration
What is the best way of diagnosing cryptorchidism?
** Anti-mullerian hormone **
* <2y/o + donkeys = hCG stimulation test
* >3y/o = oestrone sulphate assay
*Ultrasonography
* Transrectal palpation
How is cryptorchid castration carried out?
- Always open tunic to ensure whole testicle removed
- Always remove cryptorchid testicle first
What are miscellaneous diseases of the male repro tract?
- Anorchidism / monorchidism
- Torsion of spermatic cord
- Testicular neoplasia
How are inguinal hernias diagnosed?
- Palpation
- Ultrasound
What should be considered in stallions and colts regarding hernias?
- Strangulating hernias if stallion / colt presenting colic
How would you treat inguinal hernias?
- Free entrapped small intestine
- Castration (uni/bilateral)
What are penile / preputial neoplasias?
- Squamous cell carcinoma
- Melanoma
- Sarcoid
How are penile neoplasias diagnosed?
- Hx + signs
- Visual apperance
- +/- biopsy
How would you treat squamous cell carcinoma?
- Medical Tx = cryotherapy, topical chemotherapeutics
- Surgery = local excision, reefing (segmental posthetomy), partial phallectomy, en bloc resection
- Euthanasia - suspected metastatic spread
What is prognosis of penile neoplasias + prevention?
- Good prognosis if treated early + appropriately
- Prevention = owner education - cleaning sheath regularly
- examination of penis as part of routine yearly check-ups in older geldings
What should be done with penile trauma?
- Ice pack + cold hosing
- NSAIDs + antibiotics
- +/- referral
- Support penis / suture within sheath with umbilical tape
What can priapism be secondary to? (persistent erection without sexual excitement)
- Acepromazine
How is priapism treated?
- Emergency in breeding season
- IV clenbuterol
- Intra-CCP phenylephrine
- LAvage CCP
What can prolonged paraphimosis lead to? (inability to retract penis into prepuce)
Tx?
- Pudendal nerve injury
- Tx = support w umbilical tape, NSAIDs, Massage
What are abnormalities of ejaculate?
- Pyospermia
-External infection
-Cystitis
-Epidydimitis
-Seminal vesiculitis - Haemospermia
-Infectious as above
-External injury – skin/urethral process
-Urethral injury/rent - Urospermia
-As above
-Neurological dysfunction
What should be done with phimosis? (inability to protrude penis)
- Treat surgically
