According to Dachshund World, Dachshunds typically have a 21-day heat cycle. The heat cycle consists of seven days going into the cycle, seven days on the cycle and seven days coming off the cycle.
Dachshunds typically have a heat cycle once every six months. The first part of the heat cycle is called proestrus and lasts four to nine days. During proestrus, Dachshunds exhibit symptoms such as swelling of the vulva and vaginal bleeding. The second part of the cycle is called estrus. Estrus is the period of time that mating occurs and can last anywhere from four to 13 days. While mating typically only occurs during estrus, pregnancy can happen at any time during the cycle.