Abstract This study designed a protocol that would combine PMSG and cabergoline to induce estrus in bitches. Twenty clinically healthy adult and anestrous female dog were randomly assigned to four groups. The first group was treated with cabergoline (5 μg/kg, PO, q 24 h, n=4) until the onset of proestrus or for 25 days. The second group was treated with PMSG (20 IU/kg, IM, n=6) for 5 days and 500 IU hCG on the fifth day. The Third Group was treated with cabergoline (5 μg/kg, PO, q 24 h, n=6) for 10 days in combination with PMSG (20 IU/kg, IM) for 5 days and 500 IU hCG on the 10th day. The control group (n=4) received 1 ml of normal saline IM daily for 5 days. Ovarian changes were evaluated ultrasonographically, and the estrus cycle phase was examined by vaginal cytology. Three, three, and four bitches showed clinical signs of proestrus in each treatment group, respectively. The intervals between treatment and proestrus for each group were 30±3.05, 7.67±1.2, and 13±1.2 days, respectively. Two weeks after estrus, the progesterone mean was 14.51±6.24, 19.96±17.16, and 19.12±9.26 ng/mL for each group, respectively. In ultrasonography examination, the largest follicle was identified at 15.66±1.33, 11.66±2.4, and 8.75±2.17 day after the onset of proestrus; and the largest follicle’s size measured 6.5±0.55, 4.83±1.64, and 7.07±1.49 mm for each group, respectively. Although the combined use of cabergoline and PMSG reduced the duration of treatment, change the duration or dosage of PMSG can be helpful to improve the results.

Keywords