Female dogs can reach sexual maturity at 7-9 months, and will begin to go into heat at this time, which is the so-called menstruation. When a female dog is menstruating, she will have symptoms such as irritability, not wanting to eat, always wanting to go out, swelling of the vulva, and bloody discharge.

Generally, a female dog’s menstrual period lasts from seven to fourteen days. The number of days of a female dog’s menstrual period is related to their own physical condition, the size of the dog, and the season. If it is affected by the secretions of other dogs in estrus, the female dog's estrus time will be shorter. If it is in seasonal estrus in spring and autumn, the menstrual period may be 15-23 days.

Dogs should pay attention to the following points during estrus

1. Dogs should use leashes when going out. They also need to provide them with nutritious, palatable and easy-to-eat food. It is not advisable to eat raw or cold food for digestion.

2. The vulva of a dog in estrus is drained of blood and mucus. It is best to put the dog in menstrual pants at home, which is cleaner and hygienic. Clean the dog's vulva regularly to keep it clean. Avoid bacterial infections.

3. Keep warm during this period and avoid catching cold. Do not take a bath during the estrus period, let alone let it lie on the cold ground for a long time.