Question of the Day

This cytology is consistent with a dog in estrus. Vaginal cytology interpretation is very useful to clinicians for timing ovulation in breeding bitches.

During diestrus vaginal smears have >50% nucleated, round-edged parabasal cells. Look for the reappearance of neutrophils (variable numbers).

Click here to see a panel of images showing canine vaginal smears with: cornified cells (estrus), non-cornified cells (diestrus), parabasal cells (anestrus), and intermediate cells (late proestrus).

Full cornification usually coincides with receptivity. Use serial serum progesterone monitoring with vaginal cytology to predict the LH surge and help estimate ovulation. 

The initial progesterone rise is considered day 0, breed twice during days 3-6 for maximal breeding success.