Log-transformed antigen-specific interferon-γ release assay results (IGRA) for M. bovisunexposed (n=9) and -exposed (n=31) wild dogs (Lycaon pictus). A diagnostic cut-off value of 51 pg/ mL was calculated as the mean +2 SD of the Mycobacterium bovis-unexposed cohort (dashed line). Medians for each group are indicated by horizontal bars. Significant differences are indicated as *** (P<0.001).