# Cryptorchidism in Equid: A Retrospective Study on Diagnostic Approach, Anaesthesia Management, Surgical Treatment and Outcomes

## TL;DR

This study examines the diagnosis, treatment, and outcomes of cryptorchidism in equids, focusing on surgical techniques and breed patterns.

## Contribution

The study provides new insights into the surgical management and genetic factors of cryptorchidism in equids.

## Key findings

- Ultrasound correctly identified retained testis location in 87% of cases.
- Standing flank laparoscopy was the most common surgical approach, used in 82% of cases.
- Quarter Horse-type horses were overrepresented, suggesting a possible genetic component.

## Abstract

Cryptorchidism is a sexual development commonly encountered in equid males. This study retrospectively analyses cases of cryptorchidism in equid referred to specialised centres, including horses, a donkey and a female intersex horse. This study provides specific information on breed, diagnostic approach, surgical treatment, anaesthesia plan, surgical complications and follow-up. The findings add information on this condition, widely spread among equid, and the possible surgical approaches.

Over the years, various diagnostic and surgical techniques have been developed to recognise and treat cryptorchidism in equid. This study retrospectively analysed cases of cryptorchidism referred to two centres between 2012 and 2025. Clinical data collected included species, breed, age, gender, location of retained testis, diagnostic approach, anaesthesia plan and surgical treatment, perioperative medical treatment, intra-operative complications and outcomes. A total of 37 clinical cases were included, 1/37 was a donkey and 1/37 was an intersex female. Most of the horses were three years old and belonged to western riding horse breeds. Ultrasound examination correctly identified the location of the retained testis in 87% of cases. The anaesthesia plan includes a local anaesthesia block, mainly a local injection for the infiltration of the retained testis. The laparoscopic standing flank technique was the main approach, performed in 82% of cases. Complications were encountered in 9% of cases, and the median discharge time was 2 days. In our study, Quarter Horse-type horses were overrepresented, and three horses were sons of the same Quarter Horse stallion, suggesting a genetic component in aetiology. The use of ultrasound might confirm cryptorchidism in both abdominal and inguinal locations. Standing flank laparoscopy was the most frequently chosen procedure, over recumbent laparoscopy and inguinal open orchiectomy. The outcome reported a low rate of intra-operative complications.