HERD HEALTH
PIH-37
pork
industry handbook
COOPERATIVE EXTENSION SERVICE • PURDUE UNIVERSITY • WEST LAFAYETTE, INDIANA
Mastitis, Metritis, Agalactia (MMA)
Authors
Charles E. Martin, University of Missouri
William C. Wagner, University of Illinois
Ronnie G. Elmore, University of Missouri
Richard F. Ross, Iowa State University
Reviewers
Lowell Breeden, Kansas State University
R. F. Nachreiner, Auburn University
Swine agalactia (in the past commonly referred to as MMA or mastitis, metritis, agalactia) is a disease syndrome that results in death of baby pigs through starvation and an increased susceptibility to other fatal diseases of the newborn. This disease is of major importance to the pork producer because of its economic impact. The typical swine agalactia syndrome occurs in the very early stages of lactation. If the herdsman or attendant has been trained to recognize the signs, it may be evident to him at farrowing. Total lack of milk (agalactia) does not occur as frequently as a reduction in normal amounts of milk (hypogalactia). The latter can easily be overlooked; and the assumption that the baby pigs were born weak is often believed as truth when, in reality, the pigs are slowly starving. The number of sows or gilts affected with this disease syndrome during a farrowing period in a given herd varies from 0% to 100% with an average of 13.1%.

Signs and Symptoms
The disease complex can be present at farrowing time or can appear within several days after parturition. Signs or symptoms observed in the sow or gilt may include rapid breathing, depressed attitude, lack of desire to eat or drink, fever, reluctance to move about or to allow nursing. When the herdsman observes uncomfortable baby pigs, it indicates the need for closer evaluation of the sow. The mammary glands of the sow or gilt are more frequently involved than any other body part. The amount of involvement varies from only one gland to the entire udder. The affected mammary glands are usually enlarged, more firm, warmer, more sensitive, and are often discolored when compared to the other glands. Careful palpation of the mammary glands of each sow several times during the early postpartum period may reveal developing
hypogalactia and allow for treatment early in the syndrome. The presence of a purulent discharge (pus) from the birth canal does not necessarily indicate that the sow or gilt has metritis. Studies have revealed that over 60% of clinically normal sows have a discharge. Postmortem examinations of sows with agalactia have indicated that the incidence of metritis is very infrequent in this disease condition.

Tissue changes within the affected sow are variable because of the different causative agents or management factors involved. Lactation failure (agalactia) can be a primary disease or secondary to other diseases. The majority of affected animals will reveal abnormal mammary gland tissues. The changes may be characteristic of mastitis or of a partially functional gland without mastitic changes.

The area of mastitis within a gland is frequently small and has created investigator comments that the degree of mastitis could not produce the signs within the sow or the starvation in the baby pigs. The partially functional or nonfunctional gland looks and feels very similar to the gland with mastitis, which makes an accurate diagnosis difficult. The partial or nonfunctional status is believed to be the result of some insult to the hormonal sequence of events necessary to mammary gland secretion. The primary mammogens—estrogens, progesterone and prolactin—along with a number of direct and indirect synergistic hormones, are essential to full development and secretion of milk by the mammary glands. Each of these hormones must be present at the right time in the right amount to initiate and maintain lactation. Anything altering the levels of the hormones—for example, environmental stress, poor nutrition, bacterial endotoxins or improper preventive injections—can affect lactation. Other body tissue changes usually involve swelling,
Cooperative Extension Work in Agriculture and Home Economics, State of Indiana, Purdue University and U. S. Department of Agriculture Cooperating. H. G. Diesslin, Director, West Lafayette, Ind. Issued in furtherance of the Acts of May 8 and June 30, 1914. It is the policy of the Cooperative Extension Service of Purdue University that all persons shall have egual opportunity and access to its programs and facilities without regard to race, religion, color, sex or national origin.