What ‘knot’ to do whilst castrating donkeys. A retrospective comparison of ligation method on spermatic cord haemorrhage in 261 donkeys castrated by vet students in rural Malawi using transfixing and modified millers' ligatures

Background

Special considerations for donkeys undergoing castration compared with horses include the presence of large scrotal vessels, larger testicular artery and vein and the consequential increased risk of post-operative haemorrhage which necessitates spermatic cord ligation.

Aims/objectives

This retrospective study compares haemorrhagic complication rates between two methods of spermatic cord ligation in donkeys castrated in rural Malawi.

Methods

All donkeys presenting to Veterinary Education Malawi / Lilongwe Society for the Protection and Care of Animals rural large animal outreach clinics for castration between February 2020 and August 2024 that underwent castration, performed by veterinary studentswho had undergone training in surgical castration were included. From 02.2020-02.2024 a transfixing ligature was placed and from February 2024 a modified millers’ knot was placed. Age, weight and incidence of spermatic cord haemorrhage were recorded.

Results

Two-hundred-sixty-one donkeys were included, with a median age of 4 years (inter-quartile-range (IQR); 3.5). Spermatic cord haemorrhage was recorded during significantly more procedures where a transfixing ligature was placed (6; 3.8 %, confidence interval 95 % (CI): 0.7-7 %) compared with procedures where a modified millers’ knot was placed (0; 0 %, CI: 0-0 %). Age or weight did not significantly differ between treatment groups or between cases where haemorrhage was and was not recorded.

Conclusion

This is the first study to compare the outcomes between two methods of spermatic cord ligation in donkeys. The modified millers’ knot is easy to apply, provides excellent hemostasis and may be preferentially used over the transfixing ligature for ligation of the spermatic cord in donkeys undergoing castration.