نشریه التیام
سال نهم شماره 1 (بهار و تابستان 1401)

Each case of dystocia is a clinical problem that may be solved if a correct procedure is followed. The diagnosis and treatment of dystocia requires a good understanding of normal parturition and sensitivity to the welfare of both dam and offspring. Difficult birth will occur when the expulsive forces are insufficient, when the birth canal is of inadequate size and shape, or when the presenting diameter of the fetus is unable to pass through the normal birth canal because it is too large or its disposition prevents it from doing so. The incidence of dystocia in heifers has been calculated to be anywhere from three to ten times that of multiparous cows, whether in beef or dairy cattle. Risk factors for dystocia are fetal-dam disparity, abnormal fetal position, vulval, vaginal, or cervical stenosis and uterine torsion. Preventing dystocia, particularly in first-calf heifers, is a very important component of a successful reproductive program on any dairy or beef operation and there are numerous factors have been involved in the incidence of dystocia. Even when plans are in place to limit dystocia risk to an acceptable level (<15% for heifers, <5% for cows), there are still cases of dystocia in beef and dairy herds. One of the most important fundamentals for optimum dystocia management is for the owner to know when to intervene or call for assistance.

Maternal dystocia includes defects of the birth canal and defects of the expulsive forces. Defects of the birth canal would be due to the pelvic constriction, failure of cervical dilation, incomplete relaxation of the caudal vagina and vulva and other physical abnormalities causing obstruction such as remnants of the paramesonephric ducts. The expulsive force of labour is due to a combination of myometrial contractions and straining induced by the contraction of the abdominal muscles with a closed glottis. Because the abdominal muscles do not come into play until the myometrium has forced the fetus and fetal membranes into the pelvic canal and stimulated the pelvic sensory nerve receptors, it is logical to consider first the expulsive deficiencies that may arise in the myometrium. These may occur spontaneously or dependently and are called, respectively, primary and secondary uterine inertia.

The aim of manipulative procedures in the monotocous species must always be to ensure that the fetus is in normal disposition before attempting delivery. Correction of defects of presentation, position, and posture can be achieved only by intrauterine manipulation of the fetus. Retropulsion of the fetus into the uterus is essential for repositioning it. After diagnosing the cause of dystocia and deciding on a plan of action, the obstetrician should consider whether the available facilities are appropriate, and whether the equipment is adequate to carry out the treatment successfully. In severe forms of dystocia, the veterinarian should always seek the assistance of a professional colleague and consider whether it might be appropriate to transport the animal to a place with hospital facilities, provided that the animal is in a fit state to travel. Obstetrical manipulation per vaginam should be performed as cleanly as possible. It is impossible to perform them aseptically because there will inevitably be some contamination.

The aim of manipulative procedures in the monotocous species must always be to ensure that the fetus is in normal disposition before attempting delivery. Correction of defects of presentation, position, and posture can be achieved only by intrauterine manipulation of the fetus. Retropulsion of the fetus into the uterus is essential for repositioning it. After diagnosing the cause of dystocia and deciding on a plan of action, the obstetrician should consider whether the available facilities are appropriate, and whether the equipment is adequate to carry out the treatment successfully. In severe forms of dystocia, the veterinarian should always seek the assistance of a professional colleague and consider whether it might be appropriate to transport the animal to a place with hospital facilities, provided that the animal is in a fit state to travel. Obstetrical manipulation per vaginam should be performed as cleanly as possible. It is impossible to perform them aseptically because there will inevitably be some contamination.

Cesarean operation is one of the oldest surgical procedures in veterinary medicine. In farm animals practice, especially in meat producing animals, this technique is a relatively frequent and performed when normal parturition is not possible. Dystocia is the most important reason for cesarean procedure and survival of the cow and the calf, and maintenance of fertility are the main aims of cesarean in cattle. In this article, the history of this technique has been briefly mentioned and the aim of this article is to describe the indications of cesarean, decision making for surgery, preparaton of the patient, different cesarian surgical approaches, as well as post-operative cares and complications in cattle.

Injuries of the birth canal in cows (perineal lacerations, fistula…) cause significant economic loss in dairy herds. These injuries usually are associated with obstetric trauma during labor. Third degree perineal lacerations and fistula formation usually happen because of dystocia, improper repairs, abscesses and forced extractions and lead to fecal contamination of the birth canal and reduced fertility. The main reason for the birth canal and external part of the reproductive tract surgery is to restore fertility of the animal and repair the injuries associated with dystocia. In this review the causes, management, and treatment of these disorders by emphasizing on the importance of birth canal injuries in cows were discussed.

The perinatal period is the most perilous in the life of all animals. Perinatal calf mortality in the first 48 hours of life has been estimated to be between 3 and 10.3%. More than 60% of producers have reported that most of their calf mortality occurs at birth. The main causes of perinatal morbidity and mortality are , in descending order of importance , combined respiratory and metabolic acidosis , parturient trauma, hypoglobulinemia, congenital infections and deficiencies, and omphalophlebitis. Some 90% of calves that die in the perinatal period were alive at the start of calving, and so much of this loss is preventable. Management of the newborn dairy calf is best achieved through implementation of simple protocols that document the correct strategies to be followed at the herd level and the correct procedures to be performed at the individual animal level. These protocols cover management of the prepartum cow, management of calving (monitoring of eutocia and detection and management of dystocia) , and newborn calf care. Therefore, it is imperative to provide immediate evaluation and care of newborn calves to ensure calf survival and health and prevent economic losses associated with perinatal mortality.