Update on postpartum dysgalactia syndrome in sows.

Abstract

Postparturient disorders in sows represent an economically important disease complex in modern piglet production worldwide. Possible findings affecting the mammary glands and/or the reproductive tract and the sow’s general condition are summarized as a syndrome consisting of a set of symptoms such as mastitis and/or metritis. The term postpartum dysgalactia syndrome (PDS) is most commonly used (Klopfenstein et al., 2006), but other names such as mastitis–metritis–agalactia (MMA) (Martin et al., 1967), agalactia toxemica (Ringarp, 1960), agalactia complex (Penny, 1970), agalactia postpartum (Hermannson et al., 1978), lactation failure (Elmore and Martin, 1980), periparturient hypogalactia syndrome (Smith et al., 1992) or puerperal septicemia and toxemia (Bostedt et al., 1998) have been suggested, too. The predominant symptom is reduced milk production with or without apparent mastitis during the first days after farrowing (Ross et al., 1981; Wegmann et al., 1986; Heinritzi and Hagn, 1999). Increased piglet losses due to high mortality rates caused by a lack of sufficient milk production lead to a significantly reduced number of weaned piglets. Possible causes of PDS vary, and the etiology of the syndrome is clearly multifactorial (Gerjets and Kemper, 2009). In most cases, PDS is limited to a few animals and may only be sporadic. Nonetheless, almost epidemic cases in affected herds were described with documented incidence in sow herds of up to 60% (Hirsch et al., 2004). The average incidence thereof was described as being approximately 13% (Hermannson et al., 1978; Jorsal, 1983; Bäckström et al., 1984; Madec and Leon, 1992; Papadopoulos et al., 2008a). However, these epidemiological studies on incidence at herd level are not directly comparable because of different trait definitions of PDS with no commonly defined phenotype. Sows in herds of different hygienic practices and standards may show PDS. It even occurs on excellently managed farms with optimized disinfection practices. Most research on this topic was conducted between the 1970s and 1990s (Gerjets and Kemper, 2009). Despite continued research activities, no real breakthrough has been made, and no single pathway has been identified. This either confirms the multifactorial etiology or indicates that if there is one single pathway, it may be masked by other overlaying factors. Both can be expected in a syndrome defined as a set of symptoms. However, PDS is still regularly diagnosed on farms. In practice, most clinical cases can be treated effectively with anti-inflammatory drugs, hormones, or antibiotics. Nevertheless, because of the evolving need for the prudent use of antimicrobials in the last decade, a more detailed look into pathoetiology and possible prevention of PDS has become necessary. As clinical signs are as varying as possible etiologies, this review aims to summarize recent insights into PDS gained in the last decade, with a main emphasis on mastitis and its prevention by considering the respective contributory factors.