Attempted Experimental Reproduction of Porcine Periweaning-Failure-to-Thrive Syndrome Using Tissue Homogenates

Abstract

Porcine periweaning failure-to-thrive syndrome (PFTS) is characterized by anorexia and progressive debilitation of newly weaned pigs, of which some also demonstrate repetitive oral behaviour. Although no relevant porcine pathogens have been shown to be causally associated, inoculation of susceptible pigs using tissue homogenates is needed to rule out infectious etiologies. Eight snatched-farrowed porcine-colostrum-deprived (SF-pCD) pigs were inoculated with tissue homogenates made from PFTS-affected pigs orally, or combined orally, intraperitoneally (IP) and intramuscularly (IM) at day (D) 14 of age (INOC). On D21, IP and IM inoculation were repeated. Four sham-inoculated pigs served as control (CTRL). Three INOC pigs developed mixed bacterial septicemia between the first and second inoculation. All other pigs survived until termination on D49. Average daily gain (ADG) and the frequencies of diarrhea did not differ between INOC and CTRL pigs D14 and D29. Additionally, the progressive debilitation characteristic of PFTS was not observed in any pig, and repetitive oral behaviour was observed in both groups. In conclusion, PFTS was not experimentally reproduced by the current experimental approach providing evidence that PFTS may not have an infectious etiology.

Genome‐wide association study of periweaning failure‐to‐thrive syndrome (PFTS) in pigs

“…Some predisposing factors such as management, environment and nutrition have been proposed (Huang and others 2011), but they are not able to explain the clinical and pathologic manifestation of the illness. In addition, attempts to reproduce the disease experimentally were also unsuccessful, suggesting that PFTS is not associated with an infectious agent (Huang and Harding 2014).…”

“…No direct transmission of this condition has been observed among piglets, since uninfected age‐matched pigs grow and behave normally in contact with affected piglets (Huang and others 2012). Moreover, no relationship has been identified between the most common infectious agents occurring in the swine industry and PFTS (Huang and others 2012), and the disease has not yet been reproduced experimentally (Huang and Harding 2014).…”

Evidence that periweaning failure‐to‐thrive syndrome (PFTS) has a genetic predisposition

“…Most of the research on PFTS has focused on disease‐related microbial agents. However, there is growing evidence that PFTS is not related to infectious agents, with unsuccessful attempts to reproduce the disease by tissue homogenate inoculation (Huang and Harding, 2014a, b). The data suggest an individual genetic influence by which some boars produce a higher number of PFTS‐affected piglets.…”

Unusual histopathologic features in thymic corpuscles associated with porcine periweaning failure-to-thrive syndrome

“…8 The etiology of the disease remains unclear, and attempts at experimental reproduction using tissue homogenates have failed, suggesting that the syndrome may not have an infectious etiology. 7 Individual genetic susceptibility to this syndrome has been reported. 12 Genomic regions containing genes that have been linked to phenotypes associated with the syndrome, such as depression and intestinal villus atrophy, have been identified in PFTS-affected piglets.…”