Granulosa cell tumor in Arabian mares: prevalence, risk factors, clinical and histopathological findings and outcome of surgical removal.
Authors: Derar Derar, Ali Ahmed, Al-Sobayil Fahd, Refaai Walid
Journal: Frontiers in veterinary science
Summary
# Granulosa Cell Tumors in Arabian Mares: Prevalence, Risk Factors, and Fertility Recovery Granulosa cell tumors (GCTs) remain the most common ovarian neoplasm in mares, yet breed-specific epidemiological data—particularly for Arabians—have been sparse until now. This retrospective analysis of 807 Arabian mares across 35 Saudi studs identified 24 confirmed GCT cases (0.6% prevalence) and scrutinised clinical presentation, diagnostic imaging, endocrine profiles, and histopathological findings alongside surgical outcomes in 20 treated animals. Anabolic steroid administration emerged as a potent risk factor, increasing odds of GCT development by over 13-fold, whilst stallion-like behavior (58.3% of cases), anestrus (33.3%), and contralateral ovarian atrophy (75%) proved reliable clinical indicators; histopathology distinguished adult-type tumors (76.5%) from juvenile variants, and elevated preoperative testosterone normalised in 72.7% of mares post-ovariectomy. Unilateral ovariectomy achieved an impressive 80% behavioral recovery rate with 68.8% of mares subsequently conceiving, making early surgical intervention a justified and fertility-preserving option for affected breeding animals. These findings carry clear implications for stud farm management protocols: vigilant screening of older mares showing unexplained behavioral changes, strict limitation of anabolic steroid use in breeding programmes, and prompt referral for ultrasound and endocrine assessment when GCT is suspected will substantially improve outcomes and preserve valuable genetic lines.
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Practical Takeaways
- •Avoid anabolic steroid use in breeding mares, as it significantly increases GCT risk; if steroids are used clinically, monitor ovarian status closely with ultrasonography
- •Recognize stallion-like behavior combined with anestrus or persistent estrus as red flags warranting immediate ovarian ultrasonography and hormone testing in Arabian mares
- •Early diagnosis and surgical removal of affected ovaries offers good prognosis: 68.8% of mares recover breeding function after unilateral ovariectomy
Key Findings
- •Overall prevalence of GCT in Arabian mares was 0.6% (24/807 cases identified)
- •Anabolic steroid use was a significant risk factor with odds ratio of 13.21 (p=0.0001)
- •Stallion-like behavior was the most frequent clinical sign (58.3%), with contralateral ovarian atrophy in 75% of cases
- •Unilateral ovariectomy resulted in 80% recovery rate with 68.8% of mares regaining fertility postoperatively