Shortening of Interestrous Intervals With Cabergoline in Bitches: A Clinical Trial

Two consecutive interestrous intervals (n=46) were recorded in 23 bitches of different breeds. At varying times after day 100 from the onset of the second proestrus, cabergoline (5 μg/kg per os q 24 hours) was administered from early (n=11), mid- (n=10), and late (n=2) anestrus until 2 days after the beginning of the following proestrus. Interestrous intervals (IEI) were significantly shorter in the cabergoline-treated time periods when compared to the nontreated IEI (184±4.5 days versus 239±4.5 days; P<0.01). The mean number of days of cabergoline treatment until the onset of proestrus was 21.4±2.9 (least square means and standard error of the mean [LSM±SEM]). Mean cabergoline treatment durations beginning in early, mid-, and late anestrus were 27.4±3.7, 17.6±3.8, and 5±3 days (LSM±SEM), respectively. A significant correlation was found between the stage of anestrus in which the treatments began and the duration of the treatments required to induce estrus (0.51, P=0.01).