When a dog has his period, it is estrus. Estrus shows as follows: vulvar edema, bleeding (some initial bleeding is not easy to find, a large number will drip to the ground), high mood, aversion to food, and always want to go out. These are all signs of estrus. If you plan to let the dog have a baby, you can choose to let the dog breed when it is in estrus, but it is not recommended to get pregnant when it is in estrus for the first time or when it is young. It is suggested that the pregnancy time is the second estrus, or 1.5 years old or older. It is not recommended to breed at the first estrus, because some bitches with early estrus are not fully developed at this time, and pregnancy may affect the growth of bitches at this time. If the conditions are ok, it is best to find a male dog with little difference or the same size when breeding. First, it is easier to conceive, and second, it is not easy to cause dystocia. If you don't plan to let the dog have children, you need to pay more attention, mainly to prevent getting lost when you go out, and don't lead the dog around when you go out. It is also a good choice to do sterilization in advance, and it can also prevent the occurrence of pyometra in the elderly. Reduce the pain caused by estrus, and it is not easy to get lost because of estrus.