3 Common Diseases in Postpartum Sows: Causes, Clinical Signs, and Treatment Protocols

Sow production has a significant impact on the productivity and economic efficiency of each pig farm. Production performance depends on various factors, including genetics, husbandry techniques, housing and management conditions, feeding and nutrition, hygiene, and pathogen control.
After farrowing, sows may develop several diseases, such as mastitis, metritis, and agalactia. If these conditions are not detected and treated promptly, they can adversely affect the sow’s health, milk production, and the growth and development of her piglets.
In this article, the Fivevet Field Technical Department will share the causes, clinical signs, prevention measures, and treatment approaches for three common diseases in postpartum sows. 1. Mastitis
1.1. Causes of Mastitis
Mastitis in sows occurs when bacteria enter the mammary gland through cracks, abrasions on the teat skin, or the opening of the teat canal.
Bacteria from the skin surface, the farm environment, or piglets' mouths can invade the teat canal, multiply, and cause swelling, redness, pain, and inflammation of the mammary gland.
Other contributing causes and predisposing factors include:
- Milk accumulation in the mammary glands due to incomplete suckling by piglets or failure to fully empty the mammary glands.
- Blockage of the milk ducts, preventing milk from flowing out and creating favorable conditions for bacterial growth.
- Sharp teeth of piglets or sharp edges in the farrowing pen causing abrasions or injuries to the sow’s udder and teats.
- High milk production in sows while piglets do not consume all the milk or suckle unevenly across the mammary glands.
- Secondary infection following metritis, retained placenta, or postpartum infections.
- Poor hygiene and sanitation in the housing environment, creating favorable conditions for bacterial proliferation and disease development.
After farrowing, the sow’s increased calcium requirements may lead to hypocalcemia, which can result in milk fever and mastitis. However, this condition should be differentiated from bacterial mastitis caused by infection.
1.2. Clinical Signs of Mastitis
Mastitis commonly develops within the first two days after farrowing. One or more mammary glands may be affected, and the lesions are often observed symmetrically along the two rows of mammary glands.
Common clinical signs include:
- The mammary glands become swollen, red, hot, and harder than normal.
- The sow shows signs of pain when the udder is touched or pressed.
- Reduced feed intake or complete loss of appetite.
- The sow is reluctant to lie down and allow her piglets to suckle.
- Body temperature may increase to 40.5–42°C.
- When milk is expressed from an affected gland, the milk may appear clotted or otherwise abnormal.
- If not treated promptly, the inflammation can rapidly spread to other mammary glands.
- In severe cases, the sow may experience reduced milk production or complete agalactia.
1.3. Prevention of Mastitis
To reduce the risk of mastitis in postpartum sows, the following preventive measures should be implemented:
- Thoroughly clean and disinfect the farrowing pen before the sow gives birth.
- Products such as Five-Iodine, Five-B.K.G, Five-BGF, or Five-Perkon 3S can be used to thoroughly disinfect the floor, walls, and other areas of the farrowing pen according to the instructions on the product label.
- Bathe and thoroughly clean the sow before moving her into the farrowing pen.
- Adjust the feed ration appropriately before farrowing (reduce feed intake by approximately 50%) and withhold feed on the day of farrowing to help prevent mastitis.
- Ensure that the feed is nutritionally balanced, of good quality, and does not contain excessive or imbalanced levels of minerals.
- Keep the pen floor clean and dry, and remove any sharp edges that could cause abrasions or injuries to the udder.
- Check the piglets’ canine teeth; only grind or treat them when necessary and ensure that the procedure is performed correctly.
- Remove the placenta, feces, and other postpartum waste to keep the farrowing pen clean. Do not allow the sow to eat the placenta or other waste, as this may contribute to milk fever and other postpartum disorders.
1.4. Treatment of Mastitis
When a sow shows signs of mastitis, prompt treatment should be initiated to prevent the inflammation from progressing and affecting milk production.
Mild cases:
- Five-Oxytocin may be used to stimulate milk secretion.
- Apply a warm compress to the affected teat to help reduce swelling, heat, redness, and pain. Then gently massage both rows of mammary glands to gradually soften the udder.
- Strip the affected mammary gland 4–5 times per day to remove the milk completely and help prevent the infection from spreading from the affected gland to healthy glands.
Severe cases:
One of the following antibiotics may be used: Five-Cefone@LA, Five-Cefquin, Five-Colimox@LA, etc.
These may be combined with one of the following anti-inflammatory products: Five-Ketofen, Five-Tofen@LA, Five-Mexicam, etc.
The choice of medication should be based on the sow’s actual condition, clinical examination findings, and the veterinarian’s prescription. Do not use or combine multiple antibiotics without veterinary guidance. 2. Metritis
2.1. Causes of Metritis
Metritis in sows can be caused by various factors, including:
- Improper obstetrical techniques when assisting a sow experiencing difficult farrowing.
- Repeated or forceful intervention, which can cause trauma to the reproductive tract.
- Poor hygiene and sanitation in the housing environment, creating favorable conditions for bacterial invasion.
- Contaminated or unhygienic drinking water used in the farm.
- Poor hygiene of the sow’s external genitalia.
- Boars affected by urethritis, balanoposthitis, or penile inflammation during natural mating.
- Rigid or contaminated artificial insemination equipment, or improper disinfection, which can cause trauma and introduce bacteria into the reproductive tract.
- Inadequate intake of vitamins A, D, and E, which can cause dryness of the mucous membranes, making them more susceptible to trauma and bacterial infection.
- Inadequate or excessive dietary protein before, during, and after pregnancy.
- Poor nutrition, resulting in weakened sows, nutritional deficiencies, and reduced resistance to infection.
2.2. Clinical Signs of Metritis
Metritis may develop 1–2 days or 8–10 days after farrowing, with two main clinical forms:
– Catarrhal metritis:
This form usually occurs 12–24 hours after farrowing. Uterine discharge is thin and watery, clear, cloudy, or contains small particles, with a fishy odor. The sow may have a mild fever.
– Purulent metritis:
Clinical signs are more pronounced in this form. The sow develops a fever, with body temperature increasing to 40–41°C, and may die if not treated promptly. Inflammatory exudate accumulates in the uterine cavity. Thick, cloudy yellow pus, sometimes mixed with blood, is discharged from the vulva. The discharge is sticky and has a foul, fishy odor. The condition usually lasts 3–4 days.
Milk production may decrease or cease completely, while piglets may develop diarrhea, become stunted, and gradually die. Severely weakened sows may die; even if they recover after treatment, they should generally not be retained for future breeding.
2.3. Prevention of Metritis
To prevent metritis in postpartum sows, the following measures should be implemented:
- Keep the farrowing pen clean and hygienic before and after farrowing.
- Thoroughly clean and disinfect the hands of personnel assisting with farrowing and all obstetrical equipment.
- Intervene during farrowing only when necessary and ensure that proper techniques are followed.
2.4. Treatment of Metritis
When a sow shows signs of metritis, treatment should be initiated promptly. Management should include uterine flushing, infection control, fever reduction, anti-inflammatory therapy, and support for the expulsion of postpartum uterine discharge.
The following measures may be applied:
- Flush the uterus using one of the following solutions: 10% iodine solution diluted at 10ml in 2L of water, 0.9% physiological saline, a concentrated decoction of betel leaves, or 0.1% Rivanol solution. Perform uterine flushing twice daily during the first 2 days, then once daily from day 3 to day 5 after farrowing.
- Reduce fever with Five-Anagin.C.
- Administer one of the following antibiotics: Five-Genamox, Five-Cefquin 25, or Five-Amox@LA.
- Combine with one of the following anti-inflammatory products: Five-Ketofen, Five-Tofen@LA, Five-Mexicam.
- Administer Five-Oxytocin at a dose of 2–4ml per sow, once daily, to support uterine contractions, promote the expulsion of postpartum uterine discharge, and stimulate milk production.
3. Agalactia
3.1. Causes of Agalactia in Sows
Agalactia in sows may be caused by various factors, including:
- Mammary gland disorders such as mastitis, blocked milk ducts, and impaired milk secretion and ejection.
- Prolonged inadequate or nutritionally deficient feeding.
- Secondary complications associated with purulent metritis, retained placenta, infectious abortion, classical swine fever, or pasteurellosis.
- Hormonal disorders affecting milk production.
3.2. Clinical Signs of Agalactia in Sows
Agalactia commonly occurs 1–3 days after farrowing or may develop at any time during the lactation period.
Common clinical signs include:
- The udder does not become engorged with milk; no milk is released when the teats are expressed, and the mammary glands gradually become smaller before milk production ceases completely.
- Piglets vocalize frequently and move restlessly from one teat to another while suckling.
- Piglets commonly develop diarrhea, become stunted, and have a high mortality rate.
3.3. Prevention of Agalactia
To prevent agalactia in sows, the following measures should be implemented:
- Provide a nutritionally complete and balanced diet.
- Ensure that the feed ration is well-balanced and appropriate for the lactation stage.
- Prevent and promptly treat metritis and mastitis.
- Closely monitor the sow’s milk production during the first few days after farrowing.
3.4. Treatment of Agalactia
When a sow shows reduced milk production or agalactia, the underlying cause should be identified first, with priority given to treating associated conditions such as mastitis, metritis, or postpartum infections.
- Use Five-Oxytocin according to the product label and under the direction of a veterinarian to support the milk let-down reflex. Mastitis, metritis, and agalactia are three common diseases in postpartum sows. These conditions can cause reduced feed intake and milk production, weakness, and directly affect the health and growth of piglets.
To effectively prevent and control these diseases, farms should pay close attention to farrowing-pen hygiene, nutritional management, proper farrowing assistance techniques, and close monitoring of sows during the first few days after farrowing. When a sow develops a fever, refuses feed, has a swollen and painful udder, abnormal vulvar discharge, or reduced milk production, she should be examined and treated as soon as possible.
This article was compiled by the Field Technical Department – Central Veterinary Medicine JSC No. 5 (Fivevet).
Frequently Asked Questions
1. What diseases are commonly seen in postpartum sows?
The three most common diseases in postpartum sows are mastitis, metritis, and agalactia. These conditions can directly affect the health of the sow and the growth and development of her piglets.
2. What are the signs of mastitis in sows?
Sows with mastitis commonly show swollen, hot, red, firm, and painful mammary glands. The sow may develop a fever, have reduced feed intake, be reluctant to allow her piglets to suckle, and produce less milk.
3. Is postpartum vulvar discharge always a sign of metritis?
No. After farrowing, sows may normally produce a certain amount of physiological lochia. Metritis should be suspected when the discharge has a foul odor, increases in volume, or persists for an abnormally long period, especially when accompanied by fever, loss of appetite, and reduced milk production.
4. Why do postpartum sows experience agalactia?
Agalactia in sows may be caused by mastitis, metritis, blocked milk ducts, inadequate nutrition, hormonal disorders, or infectious diseases.
5. Does frequent squealing by piglets mean that the sow does not have enough milk?
Frequent squealing, competition for teats, and restless movement between mammary glands may indicate that the piglets are not receiving enough milk. The amount of milk produced, the condition of the sow’s mammary glands, and the overall health of the piglets should be checked.