Clinical experience with prostaglandin F2 alpha THAM as a luteolytic agent in pregnant and non-pregnant bitches.

: Prostaglandin F 2 alpha THAM was administered to 6 bitches at various stages after service at dosages ranging from 30-250 micrograms/kg for 2-6 days. Four bitches treated between Days 21-42 after second service did not produce pups irrespective of dosage and duration of administration. A bitch treated in the first trimester and another in the third trimester did not abort but gave birth to normal litters. Two unserved bitches were also treated in the first 20 days of metoestrus with no drop in plasma progesterone being evident. It would seem that prostaglandin F2 alpha THAM is useful as a luteolytic agent only in the second trimester. Although side effects of mild panting with occasional vomiting and/or defecation were sometimes noted at all dosage levels, they were milder at the recommended lower dosage of 30 micrograms/kg administered twice daily subcutaneously for 4 days.