Holumbiyovska, T. Holumbiiovska Т.V. Remodelling the reproductive function in female dogs while using Suprelorin implant

The dissertation is devoted to studying the effect of the Suprelorin implant on the restoration of reproductive function and for estrus induction in female dogs. Suprelorin implant is a synthetic analog of GnRH with the active substance deslorelin 4.7 mg, primarily registered as a drug for chemical sterilization of sexually mature male dogs and domestic ferrets and suppression of sexual function for at least six months. Its use outside the instructions includes the treatment of benign prostatic hyperplasia in dogs, induction of estrus in bitches, and treatment of adrenal diseases in ferrets. The effect of the implant is to ensure a stable, gradual, and constant release of the active substance, which leads to the regulation of pituitary GnRH receptors, their inhibition, and desensitization. Oversaturation of GnRH gonadotropin receptors makes it possible to exclude the reproductive function for a while with its subsequent restoration. The increased availability of exogenous GnRH at the beginning of the action of the implant leads to the secretion of gonadotropins, which causes the estrus phase. This phenomenon is known as the flash effect, which leads to the induction of estrus in almost 100% of adult bitches when Deslorelin implants are used. Therefore, the Suprelorin implant with the active substance deslorelin 4.7 mg, at the beginning of its action, causes the appearance of estrus and can be successfully used to induce estrus in bitches. In terms of its mechanism of action, it is the closest to the natural sexual cycle, as it acts at the hypothalamus-pituitarygonadal level. To achieve the phenomenon of ovulation and pregnancy, it must be administered to bitches in late anestrus no earlier than 160 days after the last signs of estrus. Removing the implant in time (at the beginning of the LH peak) is also essential to prevent suppression of the sexual cycle.