Luteolysis in early diestrous beagle bitches.

To induce luteolysis early in diestrus, 15 mated beagles were treated with 250 microg/kg prostaglandin F2alpha (PG), administered subcutaneously twice daily for 4 d, from Day 5 to Day 8 after the onset of cytological diestrus. They were divided into three groups of five bitches each: Group 1 received PG only. Group 2 received PG and 20 microg/kg/day bromocryptine orally. Group 3 received PG and 0.1 mg/kg/day dexamethasone intramuscularly. Fifteen untreated beagles served as controls. In each of the three treatment groups, four of the five bitches (80%) underwent complete luteolysis and did not whelp. The three bitches which did not undergo luteolysis whelped normally. All control bitches whelped normally. It was concluded that luteolysis is possible in bitches early in diestrus and the inclusion of bromocryptine or dexamethasone did not appear to influence luteolysis.