A dog that often shows small lipstick may be in estrus. Dogs in estrus will have their testicles enter a state of active function. If you encounter or smell the smell of a female dog in heat, she may show a small lipstick. You can mate the dog, or you can take the dog for neutering surgery to solve this problem.
Sometimes dogs will leak lipstick when they are excited. Male dogs will leak when they see a female puppy in estrus, and they will also leak when they are climbing. If the glans penis prolapses slightly, don’t worry if it can retract on its own. Pay more attention as there may be some infection later.