Vaginal Smear - Mid-Estrus.

Vaginal Smear - Mid-Estrus.
Vaginal cytology indicative of estrus. Epithelial cells are superficial. Most are anuclear and some with fading or pyknotic nuclei. Note the absence of neutrophils (almost always true in estrus) and red blood cells (sometimes true in estrus), and the very clean background.

Verstegen J (2009)