Castration Complications - Horse

Introduction

Complications following equine castration are rare, however owners should be warned of all the possible complications before the procedure to allow them to make an informed decision about the operation. This also ensures that they are able to observe and recognise any potential complications post operatively. Complications can occur within hours or take many days to develop, and owners should be advised to monitor the patient closely over this period of time. If presented with a patient post castration, a full history should be obtained both from the owner and the vet who undertook the surgery if it was not yourself.

Incidence

One UK practice reported complication rates of 22% with standing, open castration and 6% with recumbent, sterile surgery with primary scrotal wound closure.

Haemorrhage

This is the most immediate and common complication and can be life-threatening depending on the extent and duration of bleeding.

Prevention

• Early morning surgery - to allow observation throughout the day
• Appropriate haemostatic technique for the animal - additional haemostasis in older animals
• Sterile technique
• High quality emasculator

Treatment

If pressure from sterile packing is not controlling the flow, the horse may need to be rapidly re-anaesthetised to locate the source of the haemorrhage. The blood may be from the large scrotal vessels, external pudendal vessels or from the testicular artery. The scrotal wound must be cleaned and the cut ends of the testicular artery located and re-ligated if necessary. The risk of infection occurring after such an emergency is high, and antibiotics will be needed. The horse must be assessed for blood loss and haemorrhagic shock, and treated accordingly.

Eventration

Omental Eventration

Small pieces of omentum, fat and fascia may prolapse out of the wound. Every effort should be made to trim the excessive omentum, fat and fascia away during surgery; if they are found hanging from the wound, they can act as a route of infection into the wound.

Treatment

Small pieces of tissue may be cut away under sedation if they are fresh; larger pieces may require removal under anaesthetic to ensure asepsis. In these cases the omentum and scrotum should be cleaned thoroughly and then the protruding omentum should be pulled further out of the wound, then ligated and transected. Rectal manipulation can then be used to return the proximal stump into the abdomen.

Prevention of recurrence

Non-surgical: the horse should be stood on a sloped plank, with the hind quarters raised higher than the front quarters for several days.

Surgical: the edges of the incised vaginal tunic at the site of the scrotal wound are grasped using haemostatic forceps. Then, the vaginal tunic should be separated from the surrounding skin and dartos fascia, then crushed proximally and ligated and transected distally.

Intestinal Eventration

This complication is rare and generally only occurs following an open castration, however it is lifethreatening and immediate action is required. It may occur either as a result of straining post-operatively in the presence of large inguinal rings, or secondary to a hernia present prior to castration. It will normally occur in the first 24 hours post-op, but can occur up to one week following surgery.

Treatment

1) If extended to the level of the thighs:

• Wrap in a moist clean sheet and rubbish bag to prevent further contamination
• Wash the intestines with warm saline and antibiotic solution
• Identify the vaginal tunic and feed the intestines back through the inguinal ring with or without extending the inguinal ring cranially via a midline laparotomy
• Suture closed or pack the external inguinal ring
• If the bowel is compromised or damaged it may require resection.
• Systemic antibiotics, anti-endotoxins and fluids should be administered

2) If extended to ground and trodden:

• Hopeless prognosis
• Euthanasia the only appropriate treatment

Oedema

This is clinically normal in uncomplicated cases. It can be marked and may extend to the front legs.

Treatment

• Cold hose the area for 10 minutes twice a day
• Walk the horse for 10 minutes three times a day
• Administration of anti-inflammatories
• Breakdown of the wound edges with sterile gloved hands if severe as this allows the fluid to drain.

Infection

Infection can be superficial and easily dealt with, or deeper, leading to involvement of the vaginal tunic and scirrhous cord. Any suspicion of infection should be promptly investigated under sedation using a gloved hand. The owners may report a reduction in appetite and the horse have a stiff gait. The wound itself may be swollen and discharge may be present. Clinical signs include an increase heart rate, respiratory rate and temperature if the infection is severe.

Champignon is a specific infection that is normally caused by Streptococcus zooepidemicus. It produces mushroom-like growths of granulation tissue from the wound. It is associated with the use of ligatures. Drainage and surgical removal of diseased tissue is necessary to treat this condition.

Treatment

Local superficial infection is best dealt with by enlarging the incision sites to improve drainage, cold hosing and walking as for oedema and a course of antibiotic treatment. If infection is within the vaginal tunic or spermatic cord (scirrhous cord), repeat surgery is required to resect all affected tissue and this may need to be combined with scrotal ablation if the scrotal tissue is also oedematous and infected.

Hydrocoele

This presents as a circumscribed, painless swelling which is filled with a sterile, clear, straw-coloured fluid. Fluid gradually builds up, so may not be noticed until several weeks or months after castration. It is more common with open castration.

Treatment

Removal of the vaginal tunic under general anaesthesia

Persistent Stallion-like Behavior

This is a common problem but is rarely due to retained testicular tissue. Instead it is attributed to learned behaviour.

Castration Complications - Horse Learning Resources
Flashcards Test your knowledge using flashcard type questions	Equine Reproduction and Stud Medicine Q&A 10

References

Pycock, JF (1997) Self-Assessment Colour Review Equine Reproduction and Stud Medicine Manson

RVC staff (2009) Urogenital system RVC Intergrated BVetMed Course, Royal Veterinary College

Railton, D (1999) Complications associated with castration in the horse In Practice 1999 21: 298-30

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