Castration Complications - Horse

Haemorrhage

This is the most immediate 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 excessive this 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. After cleaning and disinfection of the protruding omentum and scrotal region, the protruding omentum is drawn further exteriorly, ligated and transected. The proximal stump is replaced into the abdomen by rectal manipulation.

Prevention of recurrence

Non-surgically: the horse is placed on a sloping plank bridge or similar, with the hind quarters upwards and the front quarters downwards for some days.

Surgically: the edges of the incised vaginal tunic at the site of the scrotal wound are grasped using haemostatic forceps. Then, the vaginal tunic is freed from the surrounding skin and dartos, crushed as proximal as possible, ligated and transected distally.

Intestinal Eventration

This complication is rare and generally only occurs following an open castration. 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.

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
• Suture closed or pack the external inguinal ring
• If the bowel is compromised or damaged it may require resection.

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. Clinical signs include an increase heart rate, respiratory rate and temperature. There may also be a reduction in appetite and the horse have a stiff gait.

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, 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. It is more common with open castration.

Treatment

Removal of the vaginal tunic

Persistent Stallion-like Behavior

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

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