Cabergoline applications in early and late anoestrus periods on German Shepherd dogs

This study was performed with 18 German Shepherd female dogs whom previous cycles were recorded. Bitches were separated into three groups: two treated groups and a control one. The first group was selected from 7 bitches in early anestrous period, i.e., at the stage 108 to 124 days after the beginning of their last pro-oestrus. The second group consisted in 6 bitches in late anestrous period, i.e., at the stage 160 to 187 days after the beginning of their last pro-oestrus. The control group was constituted by 5 untreated bitches which reach their spontaneous pro-oestrus 173 to 204 days after the beginning of their preceding pro-oestrus. Cabergoline was orally given to each of the dogs of the first and second groups at a daily dose of 6 mg/kg until the onset of pro-oestrus symptoms or maximally up to 14 days. The mean time separating the beginning of the preceding pro-oestrus and the initiation of the treatment was 116.1 +/- 15.8 and 171 +/- 9.2 days for the first and the second group, respectively. The mean duration of cabergoline treatment and the mean number of bitches in pro-oestrus 14 days after the onset of the treatment were 11.3 +/- 2.8 days (5/7) and 6.6 +/- 0.8 days (6/6) in the first and the second group, respectively. When considering the cycle following the treatment, the plasma levels of progesterone ranged between 2.5-8 ng/ml on the 4(th) day of oestrus in all groups. The mean duration of the pro-oestrus (7.6 +/- 0.9, 8.7 +/- 1.0, 8.0 +/- 1.0 days, for the first, second and control groups, respectively) and oestrus (7.0 +/- 1.0, 7.0 +/- 0.7, 8.0 +/- 1.0 days, for the first, second and control groups, respectively), the mean number of pregnant bitches (5/7, 6/6, 5/5, for the first, second and control groups, respectively), the mean time lag between births and the following pro-oestrus (224.2 +/- 14.5, 215.5 +/- 14.1, 218.2 +/- 6.0 days, for the first, second and control groups, respectively) and mean litter size (6.8 +/- 1.30, 6.0 +/- 0.89, 7.2 +/- 1.5, for the first, second and control groups, respectively) did not differ between groups. In conclusion, cabergoline applications are effective to induce oestrus without deleterious effect in bitches, the efficacy being increased in late anoestrus