Comparative efficacy of bromocriptine, cabergoline and thyroxine in inducing oestrus in bitches

摘要

Forty bitches in anoestrus for more than six months from the last heat, with a serum progesterone level less than 1 ng/ml were subjected to oestrus induction trials using anti-prolactin drugs and levothyroxine, once daily orally for 20 consecutive days. The mean serum progesterone level among them was found to be 0.57pl0.03 ng/ml. Out of 10 animals treated in each group, five (50%) in Group I (bromocriptine @ 50 og/kg body weight), nine (90%) in Group II (cabergoline @ 5 og/kg body weight), eight (80%) in Group III (thyroxine @10 og/kg body weight) and seven (70%) in Group IV (thyroxine @ 5 og/kg body weight) responded by evincing proestrual bleeding. The mean (plSEM) time taken from initiation of treatment to onset of proestrual bleeding in Groups I, II, III and IV was 28pl3.39, 13.44pl3.12 (P<0.05), 24.50pl3.18 and 33pl2.21 days respectively. The mean (plSEM) duration of proestrus and oestrus in the treatment groups was 9.80pl0.86, 10.11pl0.68, 11.25pl0.88 and 10.71pl0.68 days and 7.60pl0.24, 8pl0.29, 8.5pl0.63 and 7.85pl0.46 days respectively. The conception rate in relation to the number of animals responding to oestrus induction in the treatment groups was 80%, 78%, 63% and 57%, respectively. The mean (plSEM) gestation length calculated from the last breeding date and litter size in the treatment groups varied from 60.50pl1.55 to 64.00pl0.82 days and 5.14pl0.34 to 6.40pl0.40 respectively.