Methods
Pregnant queens were assigned to two groups. Queens in the AGL group (n = 10) received AGL 10 mg/kg, twice, 24 h apart. Queens in the AGL-CLO group (n = 9) were additionally injected with a single dose of CLO (5 μg/kg) 24 h after the second dose of AGL. Progesterone, 17beta(β)-oestradiol, cortisol, oxytocin and prostaglandin F2alpha (PGF2α) metabolite were measured in sera obtained at days 0, 1 and 2, and on the day of abortion.
Results
Average gestational age in both groups was similar (AGL 38.61 ± 0.91 days vs AGL-CLO 39.39 ± 1.35 days; P >0.05). Termination rates were 80% and 100% in the AGL and AGL-CLO groups, respectively (P <0.05). Fetal expulsion time was significantly longer (P <0.001) in the AGL group (96.9 ± 6 h) compared with the AGL-CLO group (69.8 ± 3.3 h). Duration of abortion was 19.8 ± 2.6 h and 12.6 ± 1.4 h in the AGL and AGL-CLO groups, respectively (P <0.05). Both treatments were well tolerated. Significantly (P <0.05) lower serum progesterone concentrations were observed in both groups at the day of abortion and concentrations in the AGL-CLO group (4.19 ± 0.80 ng/ml) were lower than in the AGL group (9.89 ± 2.21 ng/ml; P <0.05). Conclusions and relevance: AGL and CLO combination increases pregnancy termination rate in late-term pregnant queens. In addition, CLO contributes to a decrease in luteal function in AGL-treated late-term pregnant queens.