Females are required to be boarded in GDB kennels when they are in season, usually for 3 weeks. “When she is in season the vulva will be enlarged and blood stained fluid is passed. She may go off her food a few days, urinate more frequently when out on her walks and may be down and miserable when she is about to come into season.” (from www.petplanet.co.uk)
“The first phase of the cycle is called “Proestrus” and is characterized by a swollen vulva, a bloody vaginal discharge, attraction of male dogs. She flirts with the male but will not allow him to mount. The bloody vaginal discharge is what seems to lead to the misconception that the dog is menstruating. In fact, the blood comes directly from the walls of the vagina rather than the sloughing of the uterine lining as occurs in menstruation.
The second phase of the cycle is called “Estrus” which is characterized by the change in character of the vaginal discharge from bloody to “straw colored.” At this time the female begins to allow the male to mount. It is classically the change from proestrus to estrus that ovulation occurs and the female is most fertile.
After the mating and the discharge is over, the period of “Diestrus” begins.” (Info from http://www.marvistavet.com)
