Evaluation of cabergoline as a reproductive inhibitor for coyotes (Canis latrans)

Cabergoline, a prolactin inhibitor, was evaluated on its potential use as a reproductive inhibitor for coyotes (Canis latrans). Groups consisting of six female coyotes were randomly assigned to three treatments and a control group. At 25 to 35 days after fertilization, coyotes were palpated to verify pregnancy status. If an animal was confirmed pregnant, it was dosed with 50 μg, 100 μg, or 250 μg of cabergoline, or a placebo for seven consecutive days on approximately day 40 days of gestation. Five animals dosed with 50 μg of cabergoline, three dosed with 100 μg, and three animals receiving placebo whelped; no animals treated with 250 μg whelped. No drop in serum progesterone or prolactin levels were observed for the 50 μg and 100 μg treated groups. However, progesterone levels declined below 2 ng/ml in animals treated with 250 μg. Prolactin and progesterone levels in the control group followed typical patterns observed in pregnant canines. This study suggests that cabergoline is a potential reproductive inhibitor in coyotes. Future studies should determine if the efficacy of cabergoline in terminating pregnancy in coyotes could be improved with higher doses and at earlier stages of gestation