Mycoplasma spp. are part of the normal flora of mucosal surfaces. The presence of significant numbers of Mycoplasma organisms in the vaginal tract of an intact female during anestrus can be a cause of vagin-itis, subfertility, and the subsequent whelping of weak puppies. Intact male dogs may exhibit a preputial discharge. This situation is usually seen in breeding kennels rather than in private homes with one or more individual pets. Treatment includes antibiotics such as chloramphenicol, macrolides, or clindamycin.

Canine herpes virus is an ubiquitous organism, that commonly produces infection in the dog. It may cause upper respiratory tract disease, vaginitis, abortion, stillbirths, and neonatal mortality. Herpes virus usually causes neonatal disease when the bitch is first exposed in late pregnancy. The most common cause of death in infected neonates is inadequate nutrition, hypothermia, or sepsis.