FATORES ENVOLVIDOS NOS MECANISMOS DE ABERTURA CERVICAL EM CADELAS COM PIOMETRA

In Brazil, there is a large population of female dogs at risk of developing pyometra, since only a small percentage of healthy bitches is usually submitted to elective ovariohysterectomy. Pathogenesis of canine pyometra is not fully understood and can be presented in open or closed forms characterized by the presence or absence of vaginal discharge, respectively. The cervical opening is an important factor for diagnosis, prognosis and for choosing an effective treatment. The cervical opening, regardless of the estrous cycle, would also facilitate cytological and histopathological tests for endometrial inflammatory and neoplastic processes diagnosis. Numerous factors must be considered when studying the mechanisms of cervical opening and closing, such as the serum concentration of estrogen and progesterone hormone, receptors in the uterus, the percentage of collagen in the cervix, inflammatory infiltrate, prostaglandins, interleukins and nitric oxide. The aim of this review is to elucidate the factors involved in the mechanisms of cervical opening in bitches with pyometra.