Pathohistological Findings after Bilateral Ovariectomy in Mares with Behavioral Problems.
Authors: Wolf Nadine, Hahn Joachim A, Walter Ingrid, Zablotski Yury, Zerbe Holm, Witte Tanja S
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Bilateral ovariectomy (BO) via laparoscopy effectively resolves behavioural problems in many mares, yet the pathological basis for this clinical success has remained poorly understood. Wolf and colleagues conducted a histopathological analysis of ovaries removed from 20 behaviourally problematic mares, comparing their tissue architecture and immunohistochemical markers (Ki-67, AMH, aromatase, epidermal growth factor receptor, calretinin, epithelial cadherin) against 10 granulosa cell tumours to identify occult pathology. Although serum AMH and testosterone were significantly elevated in the tumour group, immunohistochemical expression patterns in granulosa cells of large follicular structures were remarkably similar between the two groups—suggesting that subclinical neoplastic or dysplastic changes exist in ovaries that appear ultrasonographically normal. Ultrasonographic examination missed early neoplastic changes in 15% of behaviourally affected mares and anovulatory-like follicles in 30%, findings that correlated with an 85% success rate of BO in resolving behavioural signs. These results provide important justification for BO as a welfare-appropriate intervention in reproductively sound mares with intractable behavioural problems, as the removed ovaries frequently harbour pathological abnormalities that conventional imaging cannot detect—a consideration that should inform case selection and owner counselling when conservative management has failed.
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Practical Takeaways
- •Bilateral ovariectomy is an effective surgical option for behavior-problem mares, with 85% success rate; pathohistological findings now provide justification for removing clinically normal-appearing ovaries
- •Ultrasonography alone may miss early neoplastic changes and anovulatory follicles that could be contributing to behavioral issues; this supports progressing to surgery in behaviorally problematic mares when conservative management fails
- •Serum AMH and testosterone testing may help differentiate between simple behavioral problems and neoplastic ovarian disease, guiding clinical decision-making
Key Findings
- •Bilateral ovariectomy was successful in improving behavioral problems in 85% of mares with clinically unremarkable ovaries
- •Early neoplastic changes were detected pathohistologically in 15% of mares with behavioral problems despite ultrasonographic normalcy
- •Anovulatory-like follicles were present in 30% of behaviorally problematic mares
- •Serum AMH and testosterone levels were significantly higher in mares with granulosa cell tumors compared to those with behavioral problems