Surgical aspiration of a 19 centimeter ovarian follicular cyst in an embryo donor cow

Abstract

A two and a half year-old Holstein cow presented for assessment of a markedly enlarged ovary, with a fluid-filled structure measuring approximately 19 centimeters in diameter following superstimulation with follicle stimulating hormone (FSH) for embryo collection and transfer. Clinical evaluation, including transrectal palpation and ultrasonography, measurement of steroid hormone concentrations in serum and follicular fluid, and histopathologic examination of a sample obtained from the wall of the follicle-like structure during surgery were consistent with an ovarian follicular cyst. Surgical drainage of the fluid combined with medical treatment was effective in inducing cyclicity and did not result in complications (adhesion formation). New follicular cysts occurring within two weeks following the surgical aspiration were responsive to treatment with transvaginal ultrasound-guided aspiration followed by a 7-day CIDR-Synch protocol. The cow returned to cyclicity and subsequently became pregnant, producing twin bull calves within a year of initial presentation.