Clinical interpretation of vaginal cytology and serum progesterone concentration in cycling queens

In the bitch, vaginal cytology has a broadly recognized usefulness for staging the estrous cycle, due to the high sensitivity of the canine vaginal epithelium to estrogens causing changes in the cellular pattern. Conversely, it is not routinely used in queens primarily because feline ovulation does not need to be staged (as it is induced by coitus in the majority of cases) and also due to scarcity of information on cytological patterns of different phases of the feline estrous cycle as well as an unsubstantiated fear of inducing ovulation. The aim of this study was to characterize vaginal cytological patterns and standardize the interpretation of vaginal cytology of the feline estrous cycle, thus allowing a more comprehensive and extensive use of the technique in queens.