Assessment of Diagnostic Value of Post Mortem Tongue Tip Fluids for Disease Detection in Growing Pigs

Assessing whether post mortem samples can provide value for monitoring during the post-weaning stages is necessary as this methodology can be adopted by the industry when resources are scarce. The objectives of this study are to assess pathogen detection in tongue tip fluids (TTFs), oronasal swabs (ONSs), rectal swabs (RSs), and superficial inguinal lymph nodes (SILNs). Two farms (one wean-to-finish farm and one finishing farm) undergoing a porcine reproductive and respiratory syndrome virus (PRRSV) outbreak were included, and 30 dead pigs were sampled during each farm visit. For PRRSV, the diagnostic accuracy of TTF, ONS, RS, and SILN were calculated using intracardiac serum as the gold standard. We also characterized the detection of PCV-2, PCV-3, PPV-1, PPV-2, Lawsonia intracellularis, and IAV in all collected specimens. Overall, TTF and SILN had the highest sensitivity for PRRSV-2 detection (95% and 99%, respectively). Most other pathogens were detected in TTF, with the highest detection rates were for PPV-2 (99%) and PCV-2 (41%). RS had mostly good detection rates for PPV-2 (27-73%), while ONS had similar detection rates (37%) to TTF (38%) for IAV. Altogether, this indicates that post mortem specimens can provide value for pathogen detection.