Cytology dog estrus

Cytologic changes through the canine estrous cycle reflect changes in blood concentrations of estrogen. As depicted below, and described in more detail in the section on Canine Reproduction, estrogen levels rise prior to and during proestrus and fall in conjunction with the preovulatory surge of luteinizing hormone.The vaginal cytology characterizing early estrus is: high cellularity; little or no mucus and debris; no WBC's; few or no RBC's; and no parabasal cells with superficial cells predominating. Epithelial cell cornification is nearly complete approximately 2 days prior to the estrogen peak or about 4 days prior to the onset of estrus.Vaginal cytology typical of estrus, dog Vaginal cytology remains predominately superficial cells; RBCs tend to decrease but may persist throughout estrus.A dog is most fertile during the third phase of her heat cycle – the Estrus phase. The period of receptivity for girls can vary hugely from dog to dog, which is why we use ovulation testing such as cytology and progesterone testing to try to narrow that window down for successful mating.Estrus: The follicles release their eggs into the uterus and produce progesterone. Duration:  A few days to 3 weeks (typically 9 days) The start of Estrus is signified by a surge in LH that causes the release of immature eggs from the ripe ovarian follicles.