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Complications Following Orchiectomy in Stallions in Field Conditions: Descriptive Results and Predictors in a Study of 612 Cases.
Abstract: The objectives of this work were (i) to evaluate the incidence of complications in male horses after orchiectomy performed in the field, i.e., away from a veterinary hospital, (ii) to describe the post-operative complications that occurred in these animals and (iii) to study the potential predictors for the development of such complications. This study involved 612 animals, on which orchiectomy was performed. The operative part of the study was carried out by one of three experienced veterinary surgeons. Standard pre-operative procedures were followed. Orchiectomy was performed using one of three principal surgical techniques, open, semi-closed or closed, and hemostasis was achieved by means of one of the various procedures, specifically the use of the Henderson instrument, the use of the Reimer emasculator, the ligation of the testicular artery or combinations thereof. In cases of reported complications, these were verified and identified appropriately. At least one (any) post-operative complication was recorded in 145 horses (23.7%). The most frequently observed complication was scrotal swelling/seroma formation, which was observed in 130 animals (21.2% of all animals; 89.7% of animals with at least one (any) complication). Another six different complications were observed, specifically colic, continued stallion-like behavior, evisceration, funiculitis, hemorrhage and scrotal infection. The median age of horses with complications was significantly older than that of animals with no complications: 11 versus 9 years. Animals in which the open technique was applied developed post-operative complications more frequently (30.1% of animals thus operated); further, complications were observed more frequently in animals on which operations were performed by using the Henderson instrument (84.6% of animals) versus animals on which any of the various other procedures were applied (22.4%). In multivariable analysis, the following predictors emerged for the development of complications: the surgical technique employed, the procedure applied for hemostasis, older animal age, and heavier animal bodyweight. The findings confirm that orchiectomy in stallions, even when performed in field conditions, is, in general, a safe procedure. The identification of predictors suggests that veterinarians should take additional care when planning to operate on animals at higher risk or when using surgical approaches that increase the potential for the development of complications.
Publication Date: 2026-01-21 PubMed ID: 41594514PubMed Central: PMC12837701DOI: 10.3390/ani16020326Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
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Overview
- This study investigated the frequency and types of complications following orchiectomy (castration) in stallions performed outside of veterinary hospitals (field conditions).
- It identified key factors that predict the likelihood of these complications to help veterinarians reduce risks during the procedure.
Study Purpose and Design
- The main objectives were to:
- Determine how often complications occur after orchiectomy in stallions under field conditions.
- Describe the types of post-operative complications observed.
- Identify factors that predict the likelihood of these complications.
- The study included 612 stallions undergoing orchiectomy performed by three experienced veterinarians following standard pre-operative procedures.
- Three surgical techniques were used:
- Open technique
- Semi-closed technique
- Closed technique
- Various methods of hemostasis (controlling bleeding) were applied:
- Henderson instrument
- Reimer emasculator
- Ligation of the testicular artery
- Combinations of the above
Findings on Complications
- Overall, 145 horses (23.7%) experienced at least one post-operative complication.
- The most common complication was scrotal swelling or seroma formation, seen in 130 horses (21.2% of all, nearly 90% of those with complications).
- Other less frequent complications included:
- Colic (abdominal pain)
- Continued stallion-like behavior (indicating incomplete castration effects)
- Evisceration (protrusion of internal organs)
- Funiculitis (inflammation of the spermatic cord)
- Hemorrhage (bleeding)
- Scrotal infection
- Horses with complications had a higher median age (11 years) compared to those without (9 years).
Influence of Surgical Techniques and Instruments
- The open surgical technique was associated with the highest frequency of complications (30.1% of horses operated with this technique developed complications).
- The use of the Henderson instrument for hemostasis was linked to a notably higher complication rate (84.6%) compared to other methods (22.4%).
Predictors of Complications
- Multivariable statistical analysis identified several key predictors for post-operative complications:
- The surgical technique used (open technique being riskier).
- The hemostasis method (use of Henderson instrument had higher risk).
- Older age of the stallion.
- Higher bodyweight of the stallion.
Conclusions and Implications
- Orchiectomy in stallions performed in field conditions is generally safe, but nearly one in four horses may experience some complication.
- Scrotal swelling or seroma is by far the most common issue after surgery.
- The findings highlight the importance of:
- Careful choice of surgical technique and hemostasis method to minimize complications.
- Extra caution when operating on older or heavier horses with higher risk.
- Veterinarians should consider these factors during preoperative planning to enhance outcomes.
Cite This Article
APA
Tyrnenopoulou P, Flouraki E, Folias L, Loukopoulos E, Starras A, Chalvatzis P, Tsioli V, Mavrogianni VS, Fthenakis GC.
(2026).
Complications Following Orchiectomy in Stallions in Field Conditions: Descriptive Results and Predictors in a Study of 612 Cases.
Animals (Basel), 16(2), 326.
https://doi.org/10.3390/ani16020326 Publication
Researcher Affiliations
- Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece.
- Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece.
- Private Veterinary Practice, 41110 Larissa, Greece.
- Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece.
- Private Veterinary Practice, 73100 Chania, Greece.
- Private Veterinary Practice, 50100 Kozani, Greece.
- Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece.
- Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece.
- Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece.
Conflict of Interest Statement
The authors declare no conflicts of interest.
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