Post-Weaning Diarrhoea in Pigs: Welfare Management of a Critical Period

Post-weaning diarrhoea (PWD) is one of the most significant causes of morbidity and mortality in commercial pig production. It occurs when immune-naive piglets are abruptly weaned and exposed to pathogens in an unfamiliar environment.

Key Facts

Post-weaning diarrhoea typically occurs 3-7 days after weaning, when piglets lose passive maternal immunity and encounter enterotoxigenic E. coli (ETEC) in their new pen environment.
PWD causes profuse watery diarrhoea, rapid dehydration, electrolyte loss, and death if untreated — mortality rates in affected groups can reach 10-20% without intervention.
The stress of weaning itself — social disruption, dietary change, new environment — compromises immune function, increasing susceptibility to infection.
Zinc oxide at therapeutic doses (over 2,000 ppm in feed) has been highly effective in preventing PWD, but its use was banned in the EU from 2022 due to environmental contamination concerns.
Alternatives to zinc oxide include organic acids, probiotics, specific dietary proteins, vaccination programmes against ETEC, and improved hygiene protocols.
Later weaning age (28 days versus 21 days) significantly reduces PWD susceptibility by allowing more complete immune development before weaning.
All-in-all-out management of weaner accommodation — emptying, cleaning, and disinfecting completely between batches — reduces pathogen load.
Oral electrolyte supplementation for affected piglets is a welfare-critical supportive care measure that prevents dehydration mortality.

Welfare Considerations

Piglets experiencing post-weaning diarrhoea suffer acutely from dehydration, electrolyte imbalance, and abdominal cramping. The combination of weaning stress (already a significant welfare event) and subsequent infectious diarrhoea creates a profound welfare challenge concentrated in a vulnerable developmental window. Severe dehydration causes rapid deterioration — sunken eyes, skin tenting, and collapse. Death from PWD represents preventable suffering that can be substantially reduced through management choices including later weaning age, vaccination, probiotic supplementation, and improved biosecurity. The ban on therapeutic zinc oxide in the EU has created pressure to find welfare-equivalent alternatives; this represents an opportunity to address PWD through approaches that are better for both pigs and the environment.

What You Can Do

Advocate for later minimum weaning ages in pig welfare legislation — 28-day minimum weaning significantly reduces PWD incidence.
Support research into effective, environmentally safe alternatives to zinc oxide for PWD prevention.
If you farm pigs, implement all-in-all-out management and strict hygiene protocols to reduce ETEC environmental load.
Maintain oral electrolyte supplementation supplies and treat affected piglets promptly to prevent dehydration mortality.
Work with your veterinarian to develop a PWD prevention programme including vaccination and nutritional management tailored to your farm.