138 Pakistan Veterinary Journal ISSN: 0253-8318 (PRINT), 2074-7764 (ONLINE) Accessible at: www.pvj.com.pk Large Follicular Cyst in a Holstein Cow Sinem Özlem Enginler*, Mehmet Can Gündüz, Serhat Alkan 1 and Feraye Esen 2 Department of Obstetrics and Gynaecology; 1 Department of Reproduction and Artificial Insemination; 2 Department of Biochemistry, Faculty of Veterinary Medicine, University of Istanbul, Avcılar, 34320, Istanbul, Turkey *Corresponding Author: soapaydin@hotmail.com ARTICLE HISTORY ABSTRACT Received: Revised: Accepted: April 24, 2011 June 13, 2011 June 18, 2011 Key words: Estradiol 17- β Follicular cyst Holstein cow Progesterone This case report is based on a large follicular cyst (55x42 mm) in a five years old Holstein cow diagnosed by ultrasonography. The serum progesterone (P4) and estradiol 17-β (E2) levels were 2.589 ng/ml and 116.497 pg/ml, respectively at the 1st examination. The cyst started luteinization with the treatment of 10 μg i.m. GnRH and 1000 IU i.v. hCG. On ultrasonographic examination on 9 th day, cyst measured 33x31 mm. Following 500 μg PGF 2α i.m. administration, the cow exhibited signs of oestrous. Serum collected at this stage revealed P4 and E2 to be 14.438 ng/ml and 141.337 pg/ml, respectively. Three days after the PGF 2α application, the ultrasonography revealed the lysis of the luteinized cyst and P4, E2 levels were detected 0.435 ng/ml and 131.067 pg/ml, respectively. Afterward the cow had normal outward appearance. The uterus and ovaries were normal on rectal palpation. The cow was artificially inseminated and became pregnant. ©2011 PVJ. All rights reserved To Cite This Article: Enginler SÖ, MC Gündüz, S Alkan and F Esen, 2012. Large follicular cyst in a Holstein cow. Pak Vet J, 32(1): 138-140. INTRODUCTION Approximately 5.6-18.8% of dairy cows develop ovarian cysts (Kesler and Garverick, 1982). Ovarian cysts are defined as follicular structures that are larger than 2.5 cm in diameter and that persist for at least 10 days in the absence of a corpus luteum (Kesler et al., 1980; Coleman, 2008). Cysts most commonly occur during the first 60-90 days of postpartum after ovulation failure without obvious clinical signs and do not regress and maintain their growth and steroidogenesis (Vanholder, 2005). Etiology of ovarian cysts is multifactorial and it depends on the phenotypic, genetic and environmental factors. High milk yield, hot season, stress and negative energy balance may contribute for the development of cystic ovarian follicles through the metabolic adaptations that occur to sustain the animal’s high level of production (Amer and Mahdi, 2008; Braw-Tal et al., 2009). It is evident that ovarian cysts are the result of the dysfunction of the hypothalamic-pituitary-gonadal axis (Rosenberg, 2010). Cystic ovarian follicles are one of the main factors that cause subfertility in dairy cattle, as they prolong the calving interval and 10 to 30% of conception in dairy cows (Coleman, 2008; Salvetti et al., 2010). Clinical signs of cystic ovarian follicles are variable; anoestrus occurs frequently during the postpartum period both with follicular and luteal cysts, irregular estrus intervals, nymphomania, relaxation of the pelvic ligaments and masculinization can be seen during lactation period (Vanholder, 2005). Follicular cysts may be single or multiple on one or both ovaries with a thin wall (≤3 mm) and the follicular fluid is uniformly anechogenic, while luteal cysts have a thicker wall (>3 mm) with echogenic rim. Also, the latter often have echogenic spots and web- like structures in the follicular fluid. Follicular cysts produce estrogens in the absence of other follicles, this production can cease in a variable time period (Kesler and Garverick, 1982). Rectal palpation, ultrasonography and the detection of the progesterone concentrations in milk or plasma are the main diagnostic methods for the cystic ovarian structures in dairy cattle (Hooijer, 2003). Currently, human chorionic gonadotropin (hCG) and pituitary content with high LH extracts are used for treatment. Synthetic gonadotropin-releasing hormone (GnRH) has been used for the treatment of ovarian cyst successfully (Bierschwal et al., 1975; Amiridis, 2009). A good reproductive performance affects a cow’s active herd life and dairy herd economics (Vanholder, 2005). The aim of this paper is to report a 55x42 mm follicular cyst and its treatment in a 5 year old Holstein cow. History and clinical examination: A five years old Holstein cow with outward physical appearance that did not differ from cows with normal ovarian function was examined. Although she was inseminated several times but failed to conceive. The external genitalia were relaxed CASE REPORT