1. The first one is to wait for six months. If there is no estrus, there is the possibility of sterilization.

2. Another one still needs to go to the hospital for some hormone tests.

3. Observe vaginal abnormalities. When the bitch is in estrus, the change of vagina can be observed. For example: vaginal enlargement

4. Pay attention to behavior changes. When a bitch is in heat, hormones in her body will change her behavior. Usually quiet and docile dogs will become irritable, and dogs who love their families will also want to run away from home.