User:Aworuth/canine dystocia

Introduction
Three stages are recognized to occur during labor in dogs. Cervical dilatation is the first stage, followed by fetal and placental ejection in the second and third stages, respectively. The beginning of the intense contractions that indicate second-stage labor marks the end of the first stage of labor, which lasts for a definite period of time. Alternating between the second and third stages of labor, the bitch will naturally deliver one or two pups followed by one or two placentas. Anorexia, anxiety, and nesting tendencies could all be displayed by the bitch.

The term "dystocia" refers to labor difficulties. This condition can occur during any stage of labor and may be caused by maternal or fetal causes. Anomalies in the fetus' presentation, posture, and location within the uterus can have a substantial impact on the relationship between the newborn fetus and the bitch's delivery canal.

Risk factor
Canine dystocia is a common issue that increases the mortality rate for the bitch and stillbirths for the pups. Understanding the causes of canine dystocia can help in making decisions for efficient whelping management. these factors include;

Age of the bitch, litter size and parity. The risk of dystocia increases with increase in these factors.

Certain brachycephalic and terrier breeds, including Bulldogs, Boston Terriers, and Scotch Terriers, have congenitally restricted birth canals, and their fetuses may have relatively big heads, predisposing them to maternal-fetal disproportion.

Causes
Incidences of canine dystocia have been attributed to several  causes which include; uterine inertia, an inadequately sized birth canal, oversized fetus, abnormal orientation as the fetus enters the birth canal etc. These causes of dystocia are either maternal related or fetal related.

maternal causes
Maternal causes of dystocia can be morphologic or physiologic in nature. The morphologic causes of dystocia are those in which the bitch anatomical anomaly causes occlusion of the delivery canal. In narrow-hipped dogs like Bulldogs, Boston Terriers, and Scotch Terriers, where the birth canal is too narrow to allow passage of a fetus that is considered to be of normal size for the breed.

The physiologic causes involves uterine inertia is the most frequent factor in maternal dystocia, accounting for 40% to 72% of all cases. The failure of expulsion of a fetus from the uterus when there is no obstruction is known as uterine inertia, and it can be either primary or secondary. Additional physiological factors include hereditary, stress/environmental disruptions, old age, obesity, systemic disease, uterine under distention (small litter size, insufficient fetal fluids), estrogen/progesterone balance, calcium/magnesium balance, insufficient oxytocin secretion, and prematurity.

feotal causes
Fetal oversize fetal abnormalities, and abnormal fetal positioning, presentation, or posture are all fetal causes of dystocia. The most typical prenatal cause of dystocia is fetal enlargement, which can happen with prolonged gestation in unusually small litters. A mismatch between the size of the fetus and the delivery canal can result from fetal anomalies such anasarca (generalized swelling) and hydrocephalus (abnormalities of bodily fluid distribution).