HERD HEALTH
PIH-37
pork industry handbook
PURDUE UNIVERSITY • COOPERATIVE EXTENSION SERVICE • WEST LAFAYETTE, INDIANA
Lactation Failure in the Sow
Authors
Guy-Pierre Martineau, University of Montreal, Canada
Bradford B. Smith, Oregon State University
William C. Wagner, University of Illinois
Reviewers
James Bradford, Athens, Georgia
Bruce Lawhom, Texas A & M University
Donald Van Tine, Garfield, Washington
In the past, lactation failure in swine was known as “MMA” or “mastitis, metritis, agalactia.” Now it is identified as the Periparturient Hypogalactia Syndrome (PHS). Symptoms vary from death of baby pigs from starvation to increased susceptibility to other newborn pig diseases, or in its mildest form, poor performance of the litter. It is referred to as a syndrome to indicate that there may be several risk factors and clinical diseases that are referred to collectively as lactation failure or, more exactly, a temporary dysgalactia. Lactation failure is a major concern to the pork producer because of the economic impact.

The usual swine dysgalactia syndrome occurs in the very early stages of lactation. If the herdsman is trained to recognize the signs, the disease may be evident at farrowing when it severely affects the sow and/or the piglets. However, the most common form of this syndrome is not easy to recognize because clinical signs are related only to relatively poor growth performance of the litter. Under the title of lactation failure, a sow can have a variable degree of lactational impairment from a total lack of milk production (agalactia) to the more commonly encountered hypogalactia (reduction in the normal amount of secreted milk). In many cases, the sow has only a temporary reduction in the normal amount of secreted milk (hypogalactia) beginning with dysgalactia, which means that there is an impairment in the initiation of lactation. The number of sows or gilts affected with this disease syndrome during a farrowing period varies from 10% to 100%. It may be important to identify susceptible sows, i.e. primiparous (first litter) and/or multiparous sows, young and/or oldest sows.

Clinical Signs
Lactation failure can be present at farrowing time or it can appear within the first few days after parturition, or even after 10 to 14 days of successful lactation. Most sows appear nor-
mal; however, some hypogalactic sows exhibit rapid breathing, depressed attitude, lack of desire to eat or drink, fever, reluctance to move about, and refusal to allow nursing. Restless baby pigs are an indication of the need for closer evaluation of the sow.

Lactation failure is a multifactorial syndrome, and many pathways have been identified. The origin of cause may differ from herd to herd. It can start in the mammary glands, uterus, urinary tract, or gastrointestinal tract. When the primary site of disease is in the mammary glands, they may appear enlarged, firmer, warmer, and more sensitive than usual, and often discolored when compared to the other glands. Some hypo-galactic sows will, however, show little or no apparent change. Mastitis, an inflammation of the mammary glands usually caused by bacterial infections, is a frequent component in this disease syndrome. All mammary glands are rarely affected with mastitis. Careful palpation of the mammary glands of each sow several times within the first 12 to 36 hours after farrowing may reveal developing hypogalactia and allow for treatment early in the syndrome. In some sows, the affected glands may show typical signs of regression or drying off similar to that seen at weaning. In these instances, the glands probably are not mastitic. Palpation prior to farrowing can be helpful in detecting sows with excessively hard or edematous (caked) glands.

When the primary site of the disease is an infection located in the uterus and/or a urinary tract infection, there is not always a discharge. The difference between normal and abnormal vulvar discharges is difficult to determine. The presence of purulent discharge (pus) from the birth canal does not necessarily indicate that the sow or gilt has a uterine infection (metritis). Although studies have revealed that over 60% of clinically normal sows have vulvar discharge for 24 to 36 hours, this discharge is not correlated with impaired piglet growth. Discharges that persist past 36 hours often are accom-
Cooperative Extension Work in Agriculture and Home Economics, State of Indiana, Purdue University and U. S. Department of Agriculture Cooperating. H. A. Wadsworth, Director, West Lafayette, IN. Issued in furtherance of the Acts of May 8 and June 30, 1914. We adhere to the policy that all persons shall have equal opportunity and access to our programs and facilities.