Postweaning Wasting Catabolic Syndrome (PWCS)

J. Harding. Swine Health Challenges and Emerging Diseases in Western Canada. Saskatchewan Pork Industry Symposium 2009.

24-Feb-2010 (16 years 3 months 14 days ago)
The first recognized case of PWCS is in a 100 sow farrow-finish barn experiencing illness in nursery piglets shortly after weaning resulting in increased nursery mortality from base line (about 2%) to about 7%. Piglets are robust and appear healthy at weaning. Within 1-2 weeks of weaning, affected pigs demonstrate lethargy, anorexia and become thin and hairy. Within 3-4 weeks of weaning these pigs become emaciated and most are euthanized. Many have diarrhea for a short period of time, but this was not consistent. The affected pigs are not runts in that skeletal growth indicates they are normal-sized pigs before they becoming anorexic. A few less severely affected pigs may start to eat in the later stages of the disease, but these remain smaller than pen-mates, and are slow growers in the finisher barn.


Many management and medical interventions involving the farm's diets, ventilation, sanitation, and medication and vaccination programs have been attempted, but all interventions have been ineffective, with the exception of disinfecting nursery flooring with hydrated lime. Although this supports that PWCS may be caused by an infectious agent, hydrated lime is harmful if swallowed or inhaled, and causes burns to skin and eyes. Thus, its long term use as a disinfectant in affected farms is not practical.

The cause of PWCS is unknown. Extensive diagnostic testing has been performed, and
PRRS, PCV2 and other common swine pathogens have been ruled out. The disease is
currently affecting several herds in Saskatchewan, Manitoba, Ontario and
Kansas. Clinically, PWCS waxes and wanes in affected farms, and is not predictable. The majority of pigs with PWCS die, increasing mortality in 3 to 9 week old pigs from 1-2% to 6-10% on most affected farms.