Castration

Question 1

What is the primary reason horses are usually castrated?

Answer 1

(Behavior → castration renders the horse more docile and manageable; sometimes also used to alter conformation since growth plate closure is delayed in the absence of androgens)

Question 2

Describe an open castration.

Answer 2

(The vaginal tunic is incised and the testicles and cord are removed from the tunic and ligated)

Question 3

Describe a closed castration.

Answer 3

(Vaginal tunic is NOT incised, fascia is stripped from the cord and then the cord is ligated over the intact vaginal tunic)

Question 4

Describe a modified castration.

Answer 4

(Starts similar to closed, vaginal tunic is left intact and fascia is stripped away then the vaginal tunic is incised and spermatic cord is isolated, can either separately ligate the spermatic cord then ligate above tunic incision or can ligate spermatic cord and closed tunic above the tunic incision)

Question 5

What is typically the most common source of post castration hemorrhage and what can you do to fix it?

Answer 5

(Testicular artery, need to find and clamp it for 12-24 hours to facilitate coagulation; other tx options are to pack the scrotum with gauze for 12-24 hours, administer 10% formalin in 1 L of saline IV, and/or administer aminocaproic acid)

Question 6

Why should you palpate the inguinal region prior to castration?

Answer 6

(To check for inguinal hernias or enlarged inguinal rings, these can predispose for evisceration and you should know that prior to castrating)

Question 7

Which castration technique is associated with a decreased chance of evisceration?

Answer 7

(A closed castration with ligature placement)

Question 8

What is the purpose of suggesting to an owner to vigorously exercise a horse starting 48 hours post castration?

Answer 8

(Vigorous exercise is important for promoting drainage and preventing edema/infection)

Question 9

You are presented with a horse that had an open castration 5 days ago, there are signs of edema and purulent discharge from the scrotum and the horse is lame with a fever, what is most likely the issue?

Answer 9

(Septic funiculitis → infection of the spermatic cord, incidence is higher with open castrations where vaginal tunic and cremaster muscle is not removed)

Question 10

What is the difference between septic funiculitis and Champignon?

Answer 10

(Champignon is septic funiculitis but specifically caused by a Strep; characterized by a mushroom shaped mound of granulation tissue and profuse purulent discharge; if it becomes chronic → scirrhous cord)

Question 11

Why can masculine behavior continue after castration in 20-30% of cases?

Answer 11

(The horse may have learned the behavior at that point and castration was never going to fix it)

Question 12

During what age is castration typically performed?

Answer 12

(1-2 years of age)

Question 13

Optimally a horse will have been vaccinated against tetanus within how many months of castration?

Answer 13

(6 months, if not adm tetanus toxoid)

Question 14

What are the typical premed, induction, and maintenance drugs used for equine castration?

Answer 14

(Premed - xylazine, induction - ketamine (+/- diazepam, +/i guaifenesin), maintenance - incremental doses of ketamine as needed)

Question 15

How long should an owner wait to turn a gelding out with mares?

Answer 15

(1-2 months, takes up to 60 days for hormone levels to decrease)