What to Do About Dystocia in Sows? An Introduction to Correct Handling Methods
Dystocia in sows means that during farrowing or abortion, the sow cannot naturally deliver the fetuses. What should be done when a sow has dystocia? First, we must understand the causes of dystocia in sows.
Causes of Dystocia in Sows
1. Due to improper feeding and management, the sow is poorly nourished and physically weak, or the sow is too obese, lacks exercise, lacks green fodder, or is old in age and carrying too many fetuses, etc., causing weak uterine contractions and weak expulsive force. Sometimes farrowing starts smoothly, but afterward 3 to 4 remaining fetuses cannot be expelled.
2. The fetus is too large, the fetal position is abnormal, the fetus is malformed, or 2 fetuses are simultaneously wedged into the birth canal, etc., so that the fetus cannot be delivered smoothly.
3. Due to poor development of the sow, breeding too early, and other reasons, the sow's pelvis is narrow and the birth canal is narrow, affecting the delivery of the fetus.
Symptoms of Dystocia in Sows
The sow is pregnant and has reached term, shows straining and other signs of labor, but cannot smoothly deliver the piglets. In dystocia due to weak labor, there is less frequent and weaker straining, and for a long time after labor begins the fetuses cannot be delivered. In dystocia caused by fetal abnormalities, the birth canal opening and labor force are often normal, but no piglets are delivered. In dystocia due to a narrow birth canal, the vulva is not sufficiently relaxed and opened, and the labor force is normal, but only some fetal fluid flows out and no piglets can be delivered. If the labor process is too long and treatment is improper, the sow becomes weak, the heartbeat weakens, breathing becomes shallow, and in severe cases the sow dies within 2 to 3 days.
Prevention of Dystocia in Sows
Pay attention to selection of breeding stock and mating combinations, and avoid inbreeding. Sows should only be bred after 10 months of age. Be sure to give pregnant sows appropriate exercise and feed them an appropriate amount of green fodder and mineral feed, and mix the feed reasonably to prevent the sow from becoming too fat or too thin. When the sow is about to farrow, someone should be on hand to watch over her so that dystocia can be detected early and treated promptly.
Examination of the Sow's Birth Canal
Clinically, dystocia never presents as a single simple condition. It is necessary to examine the birth canal to find the main cause of the dystocia and adopt corresponding treatment measures in order to achieve good results. Examination of the birth canal is the main method for diagnosing dystocia. Restrain the sow, pull the tail to one side, wash the vulva, tail base, buttocks and nearby areas clean with clean water and soap, then rinse and disinfect with 0.1% Lysol water or 0.01% benzalkonium bromide. The examiner should cut the nails, expose the arm, and carry out the examination. With the five fingers held together, slowly insert the hand into the birth canal, feel whether insertion is difficult, and palpate whether the cervix is soft and open, how wide the opening is, whether the pelvic cavity is narrow, whether there is any injury, and whether the fetus can pass through. Then insert the hand into the uterus to touch the size of the fetus, whether it is alive or dead, whether its posture is normal, whether two fetuses are simultaneously wedged in the birth canal, etc. On the basis of this examination, decide on the treatment plan.
Assisted Delivery Measures for Dystocia in Sows
1. Manual traction. This is the use of a rope or obstetric forceps to assist the hand in removing the fetus through the birth canal. It is suitable when the fetus is too large, two fetuses are simultaneously wedged in the birth canal, the labor force is weak and the hand can reach the fetus, or when removing a malformed fetus with the aid of a fetotome, etc.
2. Drug-induced labor. It is suitable when the birth canal is relatively well opened, the fetal posture is normal, and there is simply weak labor, especially when most of the fetuses have already been delivered and only a few remain while the sow is overly exhausted and uterine contractions are weak. Subcutaneous or intramuscular injection of pituitrin injection or oxytocin 10 to 50 units is often used. To prevent strong uterine contractions, it can be injected in 4 to 5 divided doses, with an interval of half an hour between each. Note: ergot preparations will cause strong uterine contractions and should be used with caution clinically, especially when the fetus is too large or the birth canal is narrow, because misuse of ergot preparations will instead make it harder for the fetus to be delivered.
3. Cesarean section to remove the fetus. It is suitable when the pelvis is narrow, the cervix is not fully open, and the above methods are ineffective; cesarean section to remove the fetus may then be considered.