What to Do About Sow Dystocia? A Detailed Guide to Correct Handling Methods

I. Prevention of Sow Dystocia

(1) Strengthen the feeding and management of sows

Ensure that pregnant sows receive a complete and high-quality diet with an appropriate nutritional level, with particular attention to meeting the needs for vitamins and minerals closely related to reproductive function, and flexibly control feed according to comprehensive factors such as the pig's body size, parity, season, and temperature, so as to prevent the pigs from becoming too fat or too thin. Ensure the environment, especially the farrowing pen, is quiet with suitable temperature and humidity. Let pregnant sows exercise appropriately; it is best to move them into traditional pig housing for feeding 1 month before farrowing and allow them to move freely. Take careful care of sows in late gestation and sows giving birth, and monitor the entire farrowing process.

(2) Select replacement pigs strictly according to high standards

Require full and rounded hindquarters, a high tail root, and well-developed vulva. Insist on breeding at the appropriate age of over 8 months and the appropriate weight of over 110 kg, and promptly cull older sows with multiple parities.

(3) Do a good job at the epidemic prevention barrier

Adhere to the systematic epidemic prevention viewpoint, vaccinate well with various vaccines according to the immunization program, regularly disinfect, deworm, eliminate rats, and kill mosquitoes, promptly and effectively diagnose and treat various common diseases, and control the occurrence of mummified fetuses, stillbirths, and deformed fetuses.

II. Handling and Treatment of Sow Dystocia

When dystocia occurs, first drive the sow out of the gestation crate and drive her to move for about 10 min in the aisle of the farrowing house in the hope of adjusting the fetal posture, then drive the sow back into the pen to give birth. If this is ineffective, then use drugs to induce labor or perform obstetric assistance.

First, examine the state of the pelvic cavity and birth canal of the sow with dystocia, and rule out obstruction of the passage for the delivery of piglets. If the rectum is full of fecal balls pressing on the birth canal, first soften the fecal balls with slightly warm mineral oil or soapy water and remove them completely. If the bladder is filled with urine and excessively distended, pushing upward and protruding into the birth canal, repeatedly apply gentle pressure with the fingers to stimulate the bladder wall to induce urination; or force the sow to stand up and move to promote urination; if necessary, use a urinary catheter to remove the urine. If a piglet has reached the entrance of the pelvic cavity or has already entered the birth canal, immediately perform traction after assessing its size, posture, and position. The specific methods are as follows:

(1) Drug-induced labor

After confirming that the birth canal is intact and unobstructed, use drugs to induce labor. Oxytocin is the first-choice drug. It is recommended to inject 30-50 IU of oxytocin intramuscularly or subcutaneously every 20-30 min. To improve the efficacy of oxytocin, estrogen may optionally be used, that is, 10-20 mg of estradiol or other estrogen preparations may be injected intramuscularly in advance before using oxytocin.

(2) Manual obstetric assistance

1. Points to note during manual obstetric assistance

Generally, find a worker with relatively small hands, cut the nails short, remove the dirt at the edges of the nails and polish the edges of the nails, soak and wash the palms, arms, and the sow's vulva with 0.1% potassium permanganate, apply soap or paraffin oil to the palms and arms, bring the five fingers together in a conical shape and slowly rotate them into the sow's birth canal, stop inserting when the sow strains, and examine the cause of the dystocia. Never pull with excessive force during obstetric assistance, so as not to damage the sow's birth canal or cause prolapse of the birth canal.

2. Methods of manual obstetric assistance

2.1. Bare-handed traction method: The assistant slowly inserts the arm into the sow's birth canal and feels clearly the piglet's fetal position. When the piglet is in anterior presentation, use four fingers to grasp the piglet's two ears and pull slowly; you may also use the thumb and middle finger to hook the piglet's eye sockets, or use the thumb and index finger to pinch the piglet's mandibular space and pull slowly. When the piglet is in posterior presentation, use the thumb, index finger, and middle finger to hold the piglet's two hind legs and slowly pull the piglet out. If the fetal position is abnormal, first correct the piglet's fetal position, then pull. If two piglets enter the birth canal at the same time, first push one head inward, then assist delivery according to the above methods.

2.2. Instrumental obstetric assistance method: Generally, an obstetric hook and a traction rope are used. Because it causes relatively great harm to piglets and may even cause death, and may also damage the sow's birth canal, it is generally operated by someone with clinical experience. The obstetric hook can be made temporarily according to the degree of the sow's dystocia, generally using iron wire. Bend one end of the iron wire into a small hook with a diameter of about 0.5 cm and a length of about 40 cm. During obstetric assistance, place the obstetric hook in the palm and hold it with the thumb, index finger, and middle finger, form the hand into a conical shape and slowly rotate it into the sow's birth canal, and use the thumb and index finger to hook the obstetric hook onto the piglet's eye socket or mandibular space for traction. Tie one end of the obstetric rope into a slip noose, hold it with the thumb and index finger and insert it together into the birth canal, then loop it around the piglet's upper jaw or forelimbs (anterior presentation) or hind limbs (posterior presentation) and pull slowly. During obstetric assistance, traction is best performed at the same time as the sow strains.

Care of the sow after obstetric assistance: After obstetric assistance is completed, inject or place antibacterial and anti-inflammatory drugs in the uterus, use a disposable insemination tube to draw 0.1% potassium permanganate solution for flushing, once a day for 3-5 consecutive days.

2.3. Handling method for stillbirth-induced dystocia: For the very few crossbred sows nearing the farrowing period or exceeding the farrowing period for a relatively long time, with continuous discharge of lochia from the vulva and clinical signs and manifestations of farrowing, connect an insemination tube to a syringe and inject saline solution at a concentration of 1%-3% and a temperature of 36-38°C into the sow's uterine cavity until the saline solution flows out from the sow's vulva, then use oxytocin in combination. After 20 hours, the contents of the sow's uterus can be expelled. However, it must be noted that: when the sow's cervix is not open, the pelvis is narrow, and there is obstruction in the birth canal, oxytocin must not be injected; within 5 days after farrowing, 3-4 doses of penicillin and streptomycin must be injected intramuscularly each day to prevent inflammation of the reproductive tract.