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Porcine Periweaning Failure to Thrive Syndrome (PFTS) is a clinical condition characterized by anorexia, lethargy and progressive debilitation of pigs within 2-3 weeks of weaning. In affected populations, there is a striking contrast between clinically-affected pigs, which progress from having normal activity to lethargy within days of weaning, and unaffected cohorts, which grow and behave normally. The etiology and pathogenesis of PFTS are not understood, although several infectious agents have been identified in affected pigs. The objective of this report is to summarize the diagnostic investigation in a PFTS-affected farm with emphasis on identifying potential infective etiologies.
A well-managed, high health (PRRSV and M. hyopneumoniae negative; PCV2 positive) 100-sow farrowfinish farm experienced a 3.7 fold increase in nursery mortality beginning in 2007 (7.2% for 2007-2009; 1.9% for 2004-2006) almost exclusively due to PFTS. Weaned pigs show no evidence of residual illnesses from the suckling phase that could explain poor post-weaning health. Affected pigs are in good body condition at 21d weaning, and develop notable anorexia and lethargy within 7 days. Abnormal chewing or chomping behaviour is noted in a small percentage. Most die of progressive emaciation within 3 weeks. Management interventions targeting ventilation, piglet comfort, diet and water quality have not reduced PFTS-losses. PCV2 piglet vaccination and all antimicrobial strategies attempted have been unsuccessful. Losses have been partially mitigated following aggressive sanitation using hydrated lime or strong sodium hypochlorite solution. Diagnostic Investigation In response to the elevated mortality, 18 live pigs in poor body condition (PFTS) and 7 age-matched health pigs (HEALTHY) were submitted from the farm over a 30 month period. In addition, 4 healthy control pigs were submitted from each of 2 unaffected farms (CTR). Adjunct testing performed on appropriate tissues from selected pigs identified potential common swine pathogens.
No Salmonella spp., Brachyspira spp., Campylobacter spp., or Helicobacter spp. were identified in gut tissue. Testing of selected C. perfringens isolates confirmed type A (CpA). In conclusion, PFTS in the current farm is not caused by Brachyspira, PRRS, PCV2, influenza A or TGEV. HEV, PCMV, rotavirus, AEEC, CpA, enteric calicivirus and coccidiosis (probably I. suis) are present on the PFTS-affected farm, but signs do not match the reported clinical presentations for these pathogens.
J. Harding, Y. Huang, C. Auckland, B. O'connor, H. Gauvreau. Peri-weaning ailure to thrive syndrome (PFTS) diagnostic investigation to identify possible infective etiologies. 6th International Symposium on Emerging and Re-emerging Pig Diseases: 50
