During Anoestrus in the bitch, which statement is true?

• A. Lasts 3-9 months
• B. Normal behaviour
• C. No ovarian activity
• D. Hormonal events resume with follicular development as the cycle begins again

Answer: (D)

Anoestrus in the bitch is a period of reproductive quiescence between heats, with ovarian activity largely paused and hormone levels kept low. The cycle begins again when follicles start to develop in the ovaries. That follicular development triggers the resumption of the hormonal cascade—estrogen production rises, GnRH pulses increase, and FSH and LH stimulate further follicular growth and eventually ovulation. This is why the statement that hormonal events resume with follicular development as the cycle begins again is the best description.

The idea that the duration is a fixed 3–9 months isn’t accurate, since length can vary between individuals and breeds. Saying behaviour is normal doesn’t reflect the typical quiet, non-estrous state of a bitch in anoestrus. And claiming there is no ovarian activity is too absolute—there can be some minimal follicular activity, but it’s not the active, cycling ovarian function seen during proestrus and estrus. The key point is that the cycle restarts as follicles develop and hormones resume.