Vaginal Cytology of the Laboratory Rat and Mouse

Microscopic evaluation of the types of cells present in vaginal smears has long been used to document the stages of the estrous cycle in laboratory rats and mice and as an index of the functional status of the hypothalamic–pituitary–ovarian axis. The estrous cycle is generally divided into the four stages of proestrus, estrus, metestrus, and diestrus. On cytological evaluation, these stages are defined by the absence, presence, or proportion of...