At 30–48 days of gestation in a sow, which pharmacologic combination is used to lyse the corpora lutea?

• A. Prostaglandins and corticosteroids
• B. Antibiotics and steroids
• C. Vaccines and sedatives
• D. No treatment

Answer: (A)

Luteolysis to terminate mid-gestation relies on removing the progesterone support from the corpus luteum. In the sow around 30–48 days of gestation, the corpus luteum is the primary source maintaining pregnancy, so administering a luteolytic agent like prostaglandin F2 alpha triggers the CL to regress and progesterone to fall, allowing abortion to proceed.

Adding a corticosteroid enhances the abortion process by promoting fetal maturation and increasing uterine readiness for expulsion, which helps ensure the pregnancy terminates reliably within a shorter timeframe. So using prostaglandins together with a corticosteroid provides a more consistent and timely lysis of the corpora lutea and completion of abortion at this stage.

The other options don’t target luteolysis or the hormonal support sustaining pregnancy, so they don’t accomplish the intended effect.