Utvärdering av GnRH-stimulering som en metod att avgöra om en honkatt med okänd historik är kastrerad

Abstract: This study has been made to evaluate if there is a significant difference between non-estral intact versus ovariohysterectomized queens in their production of estradiol after exogenous gonadotrophin-releasing hormone stimulation. The purpose is to find a tool, which can help to diagnose if a free-roaming queen is already ovariohysterectomized or not. There are also other situations where this tool could be useful, for example to diagnose the ovarian remnant syndrome. Previous studies in bitches have shown that GnRH-stimulation is an excellent tool to diagnose the presence of ovaries in the bitch. Eleven ovariohysterectomized and eleven intact queens have been included in this study where we have analyzed plasma estradiol and progesterone concentrations before and after a single intramuscular injection of the GnRH agonist buserelin (Receptal). The results showed that there is a difference in the response to GnRH stimulation between intact and ovariohysterectomized queens. Only the intact queens responded with an increase in estradiol concentration after the GnRH stimulation. The estradiol concentration ranges of the two groups overlapped before but not after stimulation. This study demonstrates that it is possible to determine if a queen has functional ovaries by a blood test but that a previous stimulation of the ovaries is necessary to get a reliable result. This study also showed that progesterone is not useful to differentiate between ovariohysterectomized and intact queens as all except one of the 22 queens had basal progesterone concentrations before and after stimulation