Use of a decreased dose of cabergoline to treat secondary anoestrus in bitches

Abstract

The aim of the study was to determine whether a dose (0.6 mu g/kg/d) quite lower than the prolactin-lowering dose of cabergoline, prepared for humans, would be a safe and effective method for the stimulation of oestrus in bitches at secondary anoestrus or late anoestrus. Twenty-four pure blood bitches from various breeds were used in the study at their already determined periods of anoestrus. The treatment group included bitches at late and prolonged anoestrus. Eight bitches that had not shown any signs of oestrus for the preceding 370 to 485 d formed the secondary anoestrus group. Eight of the 16 bitches at late anoestrus (days 165-280) have accomplished the late anoestrus group and another 8 have been chosen randomly for the control group (untreated). Cabergoline was orally administrated until day 2 after the onset of pro-oestrus or for a maximum of 42 d. Blood samples were taken daily from each bitch during the first 5 d of behavioural oestrus to measure progesterone concentrations. In the secondary anoestrus and late anoestrus groups, oestrus was induced on days 4-14 and 12-45 at a ratio of 75.0% (6/8) and 87.5% (7/8), respectively.. The mean pro-oestrus and behavioural oestrus durations, serum progesterone concentrations on day 5 of oestrus, ovulation rates, pregnancy rates, and the mean litter sizes in secondary anoestrus, late anoestrus, and control groups were found to be similar. None of the dogs had any adverse gastrointestinal effects associated with cabergoline administration. The results of the present study suggest that the administration of 0.6 mu g/kg/d of cabergoline is a safe and effective treatment for secondary anoestrus in bitches.