Question

Which of the following drugs can be used to terminate pregnancy in she dogs?
(A). Aglepristone
(B). PGF2a
(C). Dexamethasone
(D). Cabergoline & Cloprostenol
Choose the correct answer from the options given below:

• A. (A), (B) and (D) only
• B. (A), (C) and (D) only
• C. (A), (B), (C) and (D)
• D. (B), (C) and (D) only

Hint:

Progesterone block is the key to terminating canine pregnancy.
Both receptor blockers (Aglepristone) and luteolytic agents (Prostaglandins, Prolactin inhibitors) effectively achieve this.
Aglepristone is widely considered the safest and most effective monotherapy.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Termination of unwanted pregnancy in bitches (she-dogs) can be achieved using pharmacological agents.
These agents interfere with progesterone support, which is mandatory throughout gestation in dogs.

Step 2: Detailed Explanation:
Progesterone is essential for the maintenance of pregnancy in the canine species, as they rely entirely on luteal progesterone.
Let us analyze each option:
- (A) Aglepristone is a synthetic progesterone receptor antagonist.
It competitively binds to uterine progesterone receptors, blocking progesterone action and leading to safe and reliable pregnancy termination at any stage of gestation.
- (B) $\text{PGF_{2\alpha}$} (Prostaglandin F2-alpha) is a luteolytic agent.
It lyses the corpora lutea in the ovaries, causing a rapid decline in progesterone levels and terminating the pregnancy.
- (C) Dexamethasone is a potent glucocorticoid.
When administered orally at high doses for \(10-14\) days in mid-gestation, it induces resorption or abortion of fetuses by mimicking the endocrine signals of parturition.
- (D) Cabergoline & Cloprostenol is a highly effective combination.
Cabergoline is a dopamine agonist that inhibits prolactin secretion (prolactin is luteotrophic in dogs).
Cloprostenol is a synthetic prostaglandin analogue.
Together, they act synergistically to cause luteolysis and pregnancy termination with fewer side effects than prostaglandin alone.
Since all four therapies are established and documented methods to terminate canine pregnancy, options A, B, C, and D are correct.

Step 3: Final Answer:
The drugs used to terminate pregnancy in she-dogs are (A), (B), (C), and (D), which corresponds to Option (C).