After dogs mature physically, they basically enter estrus in spring and autumn every year, probably in March and September. Dogs entering estrus will become restless, like to bark, and are unwilling to stay in the house and always want to run outside.

Dogs will become less fond of eating because of their high emotions and unsatisfied physiological desires, which will affect their appetite. This will lead to body weight loss, poor physical fitness, and vulnerability to illness. If conditions permit, dogs can be bred. After breeding, the dogs will gradually return to calmness.