Dogs that are not neutered do not necessarily have pyometra. If the dog does not mate during the estrus period and has not given birth, it will develop pyometra over time. Dogs that have given birth are less likely to have pyometra. If you do not plan to let your dog have children, it is best to have the dog neutered when it reaches adulthood. This can avoid pyometra and accidental pregnancy. Also, try not to take your dog out to play with male dogs during estrus, and pay attention to maintaining reproductive organ hygiene.