A difficult birthing experience is called Dystocia. This may be a result of maternal or fetal factors, and can be experienced during any stage of the labor. Abnormalities of presentation, posture, and the position of the fetus within the uterus can negatively affect the experience.
Uterine inactivity may be classified as primary or secondary. When the body fails to commence uterine contractions, it is called primary inertia while the secondary inertia is a cessation of uterine contractions due to fatigue – likely to occur when labor has gone on longer than the uterine muscles can handle.
There are three stages of labor.
The first stage of labor is the start of uterine contractions, relaxation of the cervix, and rupture of the chorioallantoic sac, also called water breaking. The bitch may be restless, nervous and occupy herself in nesting activity.
It is in the second stage of labor that the fetuses are pushed out by uterine contractions. The average length of delivery in dogs, from the beginning of stage two to delivery of the first offspring is usually less than four hours. The time between deliveries of subsequent offspring is usually 20–60 minutes, but may be as long as 2–3 hours. It is important to consider this variability before intervening.
The third stage delivers the fetal membranes. The bitch may alternate between stages two and three in cases of multiple fetuses. She may deliver one or two fetuses followed by one or two fetal membranes, or she may deliver a fetus followed by its accompanying fetal membrane.
The common symptoms of dystocia include
· More than 30 minutes of persistent, strong, abdominal contractions without expulsion of offspring
· More than four hours from the onset of stage two to delivery of first offspring
· More than two hours between deliveries of offspring
· Failure to commence labor within 24 hours of the drop in rectal temperature.
· Female cries, displays signs of pain, and constantly licks the vulvar area when contracting
· Prolonged gestation – more than 72 days from the day of first mating; more than 59 days from the first day of cytologic diestrus (the stage directly following the stage when conception would have occurred – can be determined by owner with vaginal swabs that are taken throughout pregnancy); more than 66 days from LH peak (luteinizing hormone, which peaks at the time of ovulation); (See Breeding, Timing)
· Discharge of uteroverdin from the vagina (a greenish-black pigment that is produced by the dog's placents), preceding the birth of the first offspring by more than two hours – indicative of premature placental separation
· Presence of bloody discharge prior to delivery of the first offspring or between fetuses
· vaginal wall to elicit abdominal straining [feathering]); the lack of this response indicates uterine inertia
