Abnormal mare behaviour is rarely associated with changes in hormonal markers of granulosa cell tumours: A retrospective study.

BACKGROUND Abnormal or undesired mare behaviours are often assumed to be associated with ovarian abnormalities. OBJECTIVES We aimed to determine the incidence of abnormal behaviours and their association with concentrations of one or more ovarian hormones associated with a granulosa cell tumour (GCT). STUDY DESIGN Retrospective descriptive. METHODS A total of 2914 hormonal profile samples submitted with the words behave, behaviour, or behaving in the submission history were analysed. The association between reported abnormal behaviours and concentrations of testosterone, anti-Müllerian hormone (AMH), inhibins and inhibin-B were assessed. Statistical analysis was performed using a Chi-squared test of association. RESULTS Of the 2914 cases that were submitted due to behaviour issues, 2506 (86%) did not have any of the measured hormones reach GCT-like concentrations. The remaining 408 cases had either one (63%), two (25.5%), or three (11.5%) hormones with concentrations consistent with those from confirmed GCT cases. Testosterone had the lowest percent of GCT-like values among the cases (7.7%), compared with AMH (9.4%), inhibins (9.6%) and inhibin B (8.7%). Stallion-like behaviour was significantly associated with increased concentrations of all four hormones. In contrast, aggression, oestrous and other abnormal behaviours were significantly less likely to be associated with increased concentrations of the hormones. MAIN LIMITATIONS Retrospective study, using sample submission history. CONCLUSION Overall, the abnormal behaviours among mares, except the stallion-like behaviour, were not associated with increased ovarian hormones. These results highlight the common misassumption about the involvement of the ovaries in 'abnormal behaviours' or 'undesirable behaviours' of mares.

[1]  H. Sieme,et al.  Active immunisation against GnRH as treatment for unilateral granulosa theca cell tumour in mares. , 2020, Equine veterinary journal.

[2]  M. R. Petersen,et al.  Moody Mares—Is Ovariectomy a Solution? , 2020, Animals : an open access journal from MDPI.

[3]  D. Hendrickson,et al.  Ovarian histopathology, pre- and post-operative endocrinological analysis and behavior alterations in 27 mares undergoing bilateral standing laparoscopic ovariectomy. , 2020, The Canadian veterinary journal = La revue veterinaire canadienne.

[4]  L. Petrizzi,et al.  Laparoscopic Ovariectomy in Standing Mule Mares. , 2020, Journal of equine veterinary science.

[5]  B. Ball,et al.  Equine granulosa cell tumours among other ovarian conditions: Diagnostic challenges. , 2019, Equine veterinary journal.

[6]  B. Kalra,et al.  Inhibin-A and inhibin-B in cyclic and pregnant mares, and mares with granulosa-theca cell tumors: Physiological and diagnostic implications. , 2018, Theriogenology.

[7]  B. Ball,et al.  Endocrine Testing for Reproductive Conditions in Horses , 2017 .

[8]  B. Ball,et al.  Biological Functions and Clinical Applications of Anti-Müllerian Hormone in Stallions and Mares. , 2016, The Veterinary clinics of North America. Equine practice.

[9]  D. Fews,et al.  Granulosa cell tumours in the mare: A review of 52 cases , 2016 .

[10]  J. Caron,et al.  Laparoscopic Ovariectomy Diminishes Estrus-Associated Behavioral Problems in Mares , 2015 .

[11]  B. Ball,et al.  Determination of serum anti-Müllerian hormone concentrations for the diagnosis of granulosa-cell tumours in mares. , 2013, Equine veterinary journal.

[12]  B. Ball,et al.  Biological and clinical significance of anti-Müllerian hormone determination in blood serum of the mare. , 2011, Theriogenology.

[13]  J. Crabtree.  Review of seven cases of granulosa cell tumour of the equine ovary , 2011, Veterinary Record.

[14]  B. Ball,et al.  Cellular localization of androgen synthesis in equine granulosa-theca cell tumors: immunohistochemical expression of 17alpha-hydroxylase/17,20-lyase cytochrome P450. , 2010, Theriogenology.

[15]  B. Ball,et al.  Expression of anti-Müllerian hormone (AMH) in equine granulosa-cell tumors and in normal equine ovaries. , 2008, Theriogenology.

[16]  T. Mair,et al.  Unilateral and bilateral laparoscopic ovariectomy of mares by electrocautery , 2008, Veterinary Record.

[17]  D. Hendrickson,et al.  Clients' Perspectives on the Effects of Laparoscopic Ovariectomy on Equine Behavior and Medical Problems , 2007 .

[18]  B. Hoffmann,et al.  Effect of ACTH (tetracosactide) on steroid hormone levels in the mare. Part B: effect in ovariectomized mares (including estrous behavior). , 2007, Animal reproduction science.

[19]  B. Lasley,et al.  Granulosa cell tumors of the equine ovary. , 2006, The Veterinary clinics of North America. Equine practice.

[20]  M. Crowe,et al.  Influence of immunization against GnRH on reproductive cyclicity and estrous behavior in the mare. , 2006, Theriogenology.

[21]  A. Tibary,et al.  Management of Estrus in the Performance Mare , 2005 .

[22]  D. Hendrickson,et al.  Use of high-power ultrasonic shears for laparoscopic ovariectomy in mares. , 2004, Journal of the American Veterinary Medical Association.

[23]  B. Colenbrander,et al.  Suppressing reproductive activity in horses using GnRH vaccines, antagonists or agonists. , 2004, Animal reproduction science.

[24]  L. Malmgren,et al.  Immunization against gnRH in mature mares: antibody titres, ovarian function, hormonal levels and oestrous behaviour. , 2002, Journal of veterinary medicine. A, Physiology, pathology, clinical medicine.

[25]  P. McCue.  Neoplasia of the female reproductive tract. , 1998, The Veterinary clinics of North America. Equine practice.

[26]  D. Varner,et al.  Effects of bilateral ovariectomy via colpotomy in mares: 23 cases (1984-1990). , 1993, Journal of the American Veterinary Medical Association.

[27]  S. McDonnell.  Behavior problem: ovaries or not? , 2017 .