The estrous cycle in dogs consists of four stages: proestrus, estrus, diestrus, and anestrus. During proestrus, the female dog's body prepares for ovulation. During estrus, the female dog is receptive to mating. Diestrus occurs when ovulation has either occurred or failed to occur, and the female dog's body begins to prepare for the next cycle. Anestrus is the period of sexual inactivity between estrous cycles.
During estrus, female dogs may exhibit certain behaviors to attract males, such as urinating more frequently, raising their tail, and becoming more playful or receptive to advances from male dogs. However, the presence of a male dog does not directly cause a female dog to go into heat or experience her period. The estrous cycle is a natural physiological process that is regulated by hormones.