Postpartum dysgalactia syndrome (PDS) has been characterized as a sow with a rectal temperature >39.5°C within 12–24 hours postpartum, detectable inflammation of one or several mammary glands (eg, redness, edema, palpable hardening, skin congestion), diminished appetite; or a combination of these signs. Piglet behavior and health may also be affected (eg, diarrhea, crushing, runting, inanition, poor growth). In more severe cases, piglet mortality is increased due to starvation.
Etiology of Postpartum Dysgalactia Syndrome and Mastitis in Sows
Postpartum dysgalactia syndrome is a multifactorial syndrome without an exact etiologic diagnosis. It is noninfectious and rare in outdoor swine production facilities. Milk samples obtained from sows affected by PDS have been found to be contaminated by Staphylococcus spp, Streptococcus spp, and mostly coliforms, thereby suggesting a fecal route of transmission. However, it is important to note that this composition of bacteria is similar to that in milk samples from healthy sows.
Affected sows show an increase in cortisol levels as well as inflammatory markers. Indeed, data show increased concentrations of TNF-alpha, interleukin-6, and C-reactive protein. Additionally, affected sows show decreased lymphocyte and neutrophil counts, which may be explained by the migration of these cells to the mammary gland.
A genetic predisposition has been suggested in sows with single nucleotide polymorphisms on the genes PRICKLE2 and NRP2 of the 17th chromosome. Selection among gilts to minimize or eliminate animals from mastitis-prone female lines can result in longterm improvement of the herd which helps to reduce the prevalence of PDS.
Clinical Findings of Postpartum Dysgalactia Syndrome and Mastitis in Sows
Clinical signs in affected sows are highly variable. Mastitis can occur in all the mammary glands or be localized to a single gland. There does not appear to be a predilection for specific mammary complexes or locations. Affected sows may seem restless. They may refuse to lie down or choose to stay on their sternum instead of their side, preventing piglets from accessing the udder. Anorexia may also occur in sows with PDS.
The impact of PDS on piglets is readily apparent, affecting their behavior and well-being. Milk ejection in affected sows is either absent or of brief duration, which causes the piglets to actively nurse for an extended time (> 5 minutes every 40 to 50 minutes). During the initial stages, piglets repeatedly attempt to nurse at frequent intervals and do not settle after nursing. Unthrifty piglets, showing signs of diarrhea, agonistic behavior, and increased mortality, are also associated with PDS.
Diagnosis of Postpartum Dysgalactia Syndrome and Mastitis in Sows
Clinical examination of sow and piglets
Careful exclusion of other differential diagnoses
Diagnosis of postpartum dysgalactia syndrome is difficult and based on clinical signs. A fever in the sow can suggest PDS, but it cannot be the only criterion, because the body temperature of sows is physiologically ~39.4°C within the first 24 hours after farrowing. Also, ~16% of sows with PDS are reported to have a body temperature < 39.5°C. 1 References The prevalence of postpartum dysgalactia syndrome (PDS), and mastitis in general, tends to be underestimated in swine herds, although it has been reported to be as high as 15%. Clinical signs... read more Therefore, diagnosis must take into account the sow’s clinical presentation as well as piglet behavior. Mammary tenderness, swelling, and teat damage are consistent with a diagnosis of lactational insufficiency. Postmortem examination is rarely performed.
It has been suggested that counts of somatic cells and polymorphous neutrophils can aid in diagnosis. However, establishing a threshold value has proved challenging because of the similarity between sub-complex involution due to poor piglet suckling and true mastitis. A threshold of 5×106 somatic cells/mL, including >70% of polymorphous neutrophils has been proposed.
Because of the non-characteristic clinical presentation of PDS, numerous pathologies can be considered as part of the differential diagnosis. Porcine reproductive and respiratory syndrome Porcine Reproductive and Respiratory Syndrome Porcine reproductive and respiratory syndrome is a viral disease first reported in 1987 in the USA and now found throughout North and South America, Asia, Africa, and Europe. There are two distinct... read more , swine influenza Influenza A Virus in Swine Swine influenza is a highly contagious respiratory disease that results from infection with influenza A virus (IAV). IAV causes respiratory disease characterized by anorexia, depression, fever... read more , metritis Pigs In cows, metritis is a common polymicrobial disease, especially within the first 2 weeks after parturition. Acute puerperal metritis refers to a severe postpartum uterine infection that results... read more , cystitis, and other causes of pyrexia and lethargy in sows should be considered.
1. Preissler R, Gerjets I, Reiners K, Looft F, and Kemper N. Prevalence of Postpartum Dysgalactia Syndrome in sows. In: Animal hygiene and sustainable livestock production. Proceedings of the XVth International Congress of the International Society for Animal Hygiene, Vienna, Austria, 3-7 July 2011, Volume 1, pp. 63-65. Tribun EU, 2011.
Treatment, Control, and Prevention of Postpartum Dysgalactia Syndrome and Mastitis in Sows
Cross-fostering of piglets to healthy sows
For treatment of postpartum dysgalactia syndrome, systemic or local therapeutic intervention (antimicrobials, NSAIDs) can sometimes be helpful, but only on a short-term basis. Antimicrobial treatment is usually started before susceptibility testing; therefore, a broad-spectrum antimicrobial is recommended. Because sows are often culled at weaning, it is important to consider withdrawal times before prescribing antimicrobial treatment. Moreover, if antimicrobials are used longterm, a dependence on them for puerperal fevers, acute mastitis, or neonatal diarrhea can develop rapidly and lead to multiresistant bacterial infections.
Cross-fostering the piglets from affected to healthy sows, as long as the health status of the litters is equivalent, is the most effective strategy in management of postpartum dysgalactia syndrome. Oxytocin (5–10 U/sow) is occasionally effective in reestablishing lactation if administered 4 or 5 times at 2- to 3-hour intervals.
Moving sows to farrowing rooms < 4 days before the expected farrowing date, inducing farrowing, feeding sows ad libitum before farrowing, and leaving sows unsupervised during farrowing increased the risk of PDS in Belgian herds. Feeding sows ad libitum during the first few days of lactation also should be considered a risk factor. At the individual level, younger sows (lower parity), sows with a high number of piglets born alive, and sows with increased number of stillbirths, births with dystocia, or increased number of interventions during birth are more likely to be affected by PDS. Therefore, sows should be monitored during farrowing, but active interventions should be limited to cases of strict necessity in which the survival of the piglet is compromised.
Seasonality and induction of farrowing seem to have an inconsistent effect on risk for disease. However, sows that are cleaner at farrowing seem to have a lower prevalence of mastitis. Washing the sows, disinfecting the farrowing rooms, and housing the sows on slatted floors may decrease the risk of mastitis.
Postpartum dysgalactia syndrome is a multifactorial and underestimated condition of swine herds.
Diagnosis of PDS is challenging and based on clinical signs of the sow and its litter.
Good swine management practices are essential to decrease the occurrence of PDS.
For More Information
1. Niemi JK, Bergman P, Ovaska S, Sevón-Aimonen M-L, Heinonen M. Modeling the Costs of Postpartum Dysgalactia Syndrome and Locomotory Disorders on Sow Productivity and Replacement. Front Vet Sci. 2017;Oct 30;4:181. doi: 10.3389/fvets.2017.00181.