The first heat depends on the breed. Yorkies mature VERY quickly. Their first heat is usually around 8 months. Again, every dog is an individual, and like women, it can happen at different ages. Sometimes it can be at 1.5 years. There are different stages to the heat cycle. 1 - Proestrus: the female attracts the males, has bloody vaginal discharge and swollen vulva and lasts about 9 days (she will NOT breed during this time). 2 - Estrus: femal will accept the male and is fertile. Ovulation usually occurs in the first 48 hours of this stage which again lasts about 9 days. 3 - Diestrus: Lasts 60-90. Reproductive tract is under the control of the hormone progesterone. This happens whether or not she is pregnant. 4 - Anestrus: No sexual activity takes place. Anestrus lasts between 3 and 4 months. |