Learn More About a Disease

Mastitis/metritis (agalaxia)

MMA (Mastitis-Metritis-Agalactia) Syndrome is one of the main causes of enzootic neonatal problems (diarrhea, squashing, and insufficient growth). It is difficult to characterize, generally due to its multiple manifestations and the difficulty of establishing an etiological diagnosis1.

The causes of the syndrome are varied (see the table below) and interrelated, which complicates diagnosis and control of the disease. The acronym MMA defines a syndrome of three pathological processes that can sometimes appear simultaneously after birth.

Metritis is the inflammation of a large part of the uterine wall. Endometritis is not as severe as metritis.

Mastitis is an inflammation of the mammary gland. While mastitis is infectious, it is not contagious, even if it affects several sows at the same time. The mammary gland is infected via an external source.

Agalactia is a partial or total loss of milk production.



Swelling and congestion
  • Constipation
  • Fear
  • Irritation
  • Excessive food
  • Lack of physical exercise
  • Falls
  • Correct the cause
  • Reduce the amount of food
  • Oxytocin and penicillin
  • Electrolytes for the litter
Mammary hypoplasia
  • Age
  • Race
  • Hormones
  • Anatomy
  • Mycotoxins
  • Limited water
  • Correct the cause
  • Replace the sows
  • Have piglets adopted by nursing sows
  • Age
  • Fat sow
  • Poorly designed farrowing crate
  • History of swelling or congestion
  • Insufficient amount of water
  • Correct the cause
  • Reduce the amount of food
  • Have piglets adopted by nursing sows
  • Replace the sow
  • Oxytocin
  • Additional milk
MMA (Mastitis-Metritis-Toxic Agalactia)
  • Help with birthing
  • Teat contamination
  • Cystitis
  • Change in diet
  • Excessive food
  • Metritis or vaginitis, nephrites
  • History of mastitis
  • Difficult birth
  • Septicemia
  • Swelling sequela and blocked udder
  • Stress
  • Check the causes
  • Bacteriological tests
  • Control food
  • Control restriction
  • Assess subclinical mastitis
  • Antibiotics
Acute mastitis
  • Poor drainage
  • Ongoing antibiotic use
  • Damaged drinking troughs
  • Piglet teeth
  • Poor environmental hygiene
  • Mediocre flooring
  • Presence of pathogenic agents
  • Sawdust or wood chip bedding
  • Trauma to teats
  • Damp floor
  • Check the causes
  • Check teat damage
  • Check teat contamination
  • Maternal hygiene and floor quality
  • Collect individual data
  • Properly clean and disinfect flooring
  • Monitor all breeding practices
  • Water
  • Antibiotics
  • Corticosteroids
  • Diuretics
  • Treatment before birth


Source: M. Muirhead and T. Alexander. Managing Pig Health and the Treatment of Disease.

Clinical Signs +

A sow with mastitis has general symptoms. Locally, fully developed mastitis manifests by marked induration of the mammary glands. Swelling is evident if an imprint remains visible for several minutes after a finger is pressed on the gland. Once mastitis has fully developed, milk can no longer be secreted (agalactia). Sick sows will not let piglets access their teats. General symptoms are fever, anorexia and listlessness, which are due to multiplying bacteria and toxin resorption. The microorganisms involved are usually E. coli, Klebsiella, Enterobacter, Citrobacter, as well as other bacteria, such as Staphylococcus or Pseudomonas aeruginosa.

In sows, metritis is characterized by purulent profuse discharges, with a brown-reddish color and the presence of necrotic and foul-smelling debris. Acute symptoms in the sow are fever and anorexia. Scarce whitish discharges should be considered normal for the first two days following birth. Numerous bacteria are likely to colonize the endometrium after birth (E. coli, Staphylococcus hyicus, Staphylococcus aureus). Etiological identification is important to adapt the treatment and to try to identify the risk factors.

Diagnosis +

Early diagnosis of acute mastitis is essential, but not always easy to establish. As it often seems to lead to discomfort for the sow, there is frequently a mistaken tendency to classify all behaviour from sows sleeping on their mammary glands as a sign of mastitis. If some teats are not occupied and the lack of milk makes the piglets excited, agalactia may be involved, especially if the piglets continue to try to suck and the sow is not producing any milk. In this case, several piglets could die from hunger.

Metritis is more easily diagnosed if details of the birth are known. In certain cases, a placental exam can prove useful. Finally, difficulties with reproduction may lead the producer to suspect metritis.

Treatment +

Sows with mastitis must receive a parenteral antibiotic. Anti-inflammatories are also recommended to reduce teat inflammation. For metritis treatment, a long-acting antibiotic is recommended in order to avoid having to give several injections.

Consult a veterinarian before administering antibiotics and vaccines to the animals.

Your veterinarian is the best person to talk to for recommendations that are right for your farm.


1 Maladies d’élevage des porcs [Hog Farm Diseases], 2nd edition, Guy Pierre Martineau

Prevention +

The mammary glands are contaminated via an external source. Very few bacteria are required to cause contamination. Mastitis cases have even been seen in farms with the most stringent hygiene measures. Predisposing factors for mastitis are environmental contamination, post-partum dysgalactia syndrome, udder edema at parturition and piglet behaviour.

Metritis is often caused by a lack of hygiene during birth. It is therefore very important to use clean and disinfected gloves or disposable gloves. A large microbial load in the birthing room provides the perfect environment for the appearance of metritis. To reduce risk, sows can be cleaned before they go to the maternity area. The corridor between the gestation room and the maternity area can be transformed into a cleaning station for sows.