Induction Estrus in Local Anestrum Bitches by using GnRH, PMSG and hCG Combination

THIS study was performed to compare the ability of GnRH alone and combination of PMSG-hCG hormones to induce of estrus in anestrus female dogs (bitches). Hence, a total of 17 local dogs; 15 bitches of 2-4 years old and 2 fertile males (2-5) years old, were selected, prepared and inseminated naturally from December 2022 to June 2023. Firstly, all bitches were divided into three groups; G1 that represents the control and leaves without treatment, G2 that received GnRH at a dose of 0.0042 mg/animal I.M for two days, and G3 that received PMSG at a dose of 40 IU/animal for 7 days and then hCG at a dose of 150 IU/animal on the 8(th) day I.M. During anestrus, the vaginal smears showed that the predominant cells were parabasal and small intermediate cells; while in estrus phase, superficial cells were the most common. Ultrasound examination for 10 treated bitches in G2 and G3 groups was made during the 19(th), 30(th), 47(th) and 59(th) days post mating. Furthermore, pregnancy rate was recorded 80% in G2 (GnRH) group and 75% in G3 group (PMSG / hCG). While, insignificant variation ( P<0.05) was seen in gestational period between G2 and G3. In conclusion, induction of estrus by using GnRH or PMSG with hCG is safe and effective.