Granulosa-theca cell tumours represent 2.5 to 4.4% of equine neoplasms, which require elective surgical approaches in order to restore fertility The retrospective study reported herein utilized the multidisciplinary approach to describe i) clinical findings and diagnostic features, ii) surgical approach, iii) and reproductive follow-up in seven granulosa-theca cell tumour affected mares. The neoplasm was diagnosed in 80% of the multiparous mares, where anestrus was the clinical feature most associated with the tumor. Furthermore, two mares displayed intermittent estrous behavior while only one showed stallion like behavior. On clinical examination of the genital tract, based upon neoplasm growth, abnormal distention of the mesovarium and ventral displacement Of the affected ovary in the abdomen, were reported. The neoplasm with a smooth surface and fluctuant areas was firm - elastic in consistency and the ovulation fossa was not detectable. Ultrasound examination per rectum well established the multicystic appearance of the neoplasm and the affected ovary; was circumscribed by a thick albuginea capsule and contained either multicystic structures, separated by mottled stroma, or oligocystic structures separated by abundant and dense hyperechoic stroma. Further ultrasonic findings were characterized by one or more anechoic follicle-like structures. The contralateral ovary was atrophied, although the neoplasm was diagnosed in both ovaries in a mare. In the present study neoplasm removal was performed either by flank grid celiotomy ipsilateral to the affected ovary or by the ventral midline approach. Gross and histological observations confirmed the presumptive diagnosis. In hemiovariectomised mares, resumption of estrous cycles occurred from 60 to 150 days after surgery. Two mares were removed from the breeding programs for management purposes, whereas the other four mares delivered seven foals during the study.
