Complications in equine transvaginal ultrasound‒guided follicular aspiration

Transvaginal ultrasound-guided follicular aspiration has revolutionised equine assisted reproduction, particularly in in vitro embryo production. This literature review examines the complications associated with transvaginal ultrasound-guided follicular aspiration in mares and its potential impact on future fertility. While transvaginal ultrasound-guided follicular aspiration is generally safe, it has inherent risks, ranging from mild rectal bleeding to severe complications such as peritonitis and acute haemorrhage. Factors influencing complication rates include veterinarian experience, mare anatomy and procedural technique. Despite concerns, studies suggest that repeated transvaginal ultrasound-guided follicular aspiration does not significantly impair future fertility, with normal pregnancy rates observed in mares undergoing artificial insemination or embryo transfer after transvaginal ultrasound-guided follicular aspiration. However, further research is needed to fully understand the long-term effects on ovarian function and oocyte quality. Veterinary practitioners must prioritise appropriate training and procedural precautions to minimise the risk of complications and safeguard mare welfare and fertility in the expanding field of equine assisted reproduction.