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

Abstract

HIS 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.