Diagnosis, Treatment and Prevention of Porcine MMA Syndrome

In September 2007, a farmer in Tangqiao Town of our city raised more than 10 sows that farrowed successively. Among them, 3 sows suddenly developed elevated body temperature on the 3rd day after farrowing, with swollen udders, refusal to let piglets suckle, continuous discharge of reddish-brown lochia from the vagina, and the vulva and surrounding area of the anus contaminated with mucus. We initially suspected uterine infection caused by retained placenta, and antibiotic treatment was ineffective. Later, comprehensive measures were adopted, the condition improved, and the animals gradually recovered. The relevant situation is described as follows:

1. Investigation of Causes and Analysis of Clinical Symptoms

The farmer had more than 10 years of @#@227@#@ history. The sows had been raised in steel-pipe partitioned pens since the year before last. Normally, the sows were kept in the partitioned pens, and after mating and 90 days of gestation they were moved into the farrowing house to await farrowing. The hygiene and disinfection work on the pig farm was done well, with daily pen cleaning and disinfection twice a week. Vaccinations against swine fever, swine erysipelas, swine pneumonia, Streptococcus suis and porcine reproductive and respiratory syndrome were given annually. In 2006, the sows farrowed smoothly and the piglet survival rate was relatively high. In September 2007, the udders turned purple with lumps inside, lochia was discharged from the vagina, and the piglets were weak and appeared hungry. We inquired about the relevant feeding and management conditions. The owner reported mainly two changes: first, a change in housing. Previously, a sow farrowing house was set up beside the isolation pens. In June 2007, a sow farrowing house was built 200 m north of the original sow barn, and this batch of sows was kept in the new farrowing house awaiting farrowing. Second, the feed was also changed. After the sows entered the farrowing house, the pregnant sow feed originally produced by a feed mill in Shanghai was changed to a self-mixed feed with a protein level of 18%, and the energy was equal to that of the original feed. The clinical symptoms were as follows: the sows had mastitis, metritis and agalactia. The sows' udders were red and swollen, with 2 to 3 hard lumps in the rear udders, increased skin temperature of the udders, and a small amount of milk flowing out or no milk when the udders were massaged. The uterus in the posterior abdomen was enlarged on palpation, and the sows groaned in pain. When firm pressure was applied, reddish-brown mucus flowed from the vagina, and the vulva and surrounding area of the anus were contaminated with mucus. The piglets were weak and appeared hungry. Based on the above clinical symptoms, we ruled out the possibility of a single disease and diagnosed it as mastitis-metritis-agalactia (MMA) syndrome.

2. Treatment and Prevention

2.1 Comprehensive treatment was adopted for the 3 sows:

(1) Antibiotic treatment: penicillin, streptomycin and dexamethasone, 2 times/d, for 5 consecutive d.

(2) To clear the lochia from the uterus, oxytocin 50 units, 2 to 4 times/d, and before injection the piglets were separated, then returned 10 to 15 min later, after which the sows could lactate.

(3) To relieve constipation and promote appetite, sodium sulfate or Glauber's salt 15 g was added to 500 mL of water for drinking, 1 time/d.

(4) Glucose, VC and VB6 were supplemented, and succulent green feed was provided.

After the above methods were adopted, except for 4 piglets that were too weak to suckle and died, the sows and the remaining piglets all recovered.

2.2 In March 2007, the sows farrowed again. We required the pig farm to adopt the following measures:

(1) The sows entered the new farrowing house after 75 d of gestation, and were transported by vehicle when being driven (last time they were forcibly pulled). The sows were allowed to adapt to the new environment.

(2) The feed was restored to the late-gestation sow feed from a feed mill in Shanghai, and the amount fed was gradually reduced one week before farrowing.

(3) The sows were given oral cefradine from 5 d before farrowing to 3 d after farrowing.

(4) To prevent loose stools before farrowing, 5 to 10 tablets of rhubarb and sodium bicarbonate were administered orally.

After the above measures were adopted, none of the sows developed MMA syndrome.

3. Discussion

3.1 Porcine MMA syndrome occurs easily on intensive pig farms. So far, its exact cause is not very clear, but it is caused by the influence of many factors alone or in combination, among which environment and feed are stress factors. The pigs that developed the disease in 2006 all experienced changes in environment and feed, especially being driven to the new farrowing house, where rough handling caused a strong reaction in the pregnant sows. At the same time, the sudden change of feed promoted the occurrence of MMA syndrome.

3.2 During treatment, comprehensive treatment methods must be used. Treatment with antibiotics alone is incomplete. Oxytocin must be used: one effect is to contract the uterus and expel dirt from the uterus and enhance intestinal peristalsis, and another is a slight galactopoietic effect. In addition, drugs that enhance physical strength, promote appetite and cause purgation should also be used in coordination. Only in this way can the intestines remain unobstructed and the body's immunity be improved.

3.3 To reduce environmental stress factors for farrowing sows, we suggest that sows in late gestation should enter a strictly disinfected farrowing house in advance, generally at 75 to 85 d after gestation. No harsh measures should be used, so that they have a relatively long period to adapt to the environment. The original feed should continue to be used and feed should not be changed suddenly. Feed reduction should begin at 113 d after gestation or when a small amount of milk can be squeezed from the teats, generally to 2/3 to 1/2 of the original amount, with sufficient clean drinking water. In addition, a small amount of antibiotics should be administered orally to achieve the purpose of antibacterial and anti-inflammatory treatment.