Use of prostaglandin F2 alpha for early pregnancy termination in the mismated bitch

Natural PGF administered at a dose of at least 250 micrograms/kg twice daily subcutaneously for at least 4 days starting no earlier than day 5 of cytologic diestrus induces luteolysis and pregnancy termination in the mated bitch. The resulting shortening of the luteal phase is associated with a shortening of the interestrous interval from 1 to 4 months. Bitches treated with PGF show emesis, diarrhea, and panting within 5 minutes and transient hypothermia which lasts 2 to 3 hours but generally have no further reaction. Bitches with cardiac or respiratory dysfunctions are not considered safe patients for early pregnancy termination with PGF because of the cardiovascular effects of this drug. Bitches treated with this regime early in diestrus resorb their conceptuses; those treated after days 35 to 40 show clinical abortion of viable fetuses.