Haptoglobin and C-reactive protein as biomarkers in the serum, saliva and meat juice of pigs experimentally infected with porcine reproductive and respiratory syndrome virus

Concentrations of the acute phase proteins haptoglobin (Hp) and C-reactive protein (CRP) were measured in the serum, saliva and meat juice of pigs experimentally infected with a porcine reproductive and respiratory syndrome virus (PRRSv) field isolate. Sixteen PRRSv-free pigs were inoculated IM, killed in groups of four at 7, 14, 21 and 24 days post-inoculation (dpi), and samples of blood, saliva and diaphragmatic muscle were collected. Four non-infected controls were killed at 24 dpi. Significant differences in lung lesions were found between PRRSv-inoculated animals and controls. Changes in the concentrations of Hp and CRP in serum, saliva and meat juice samples were similar, peaking at 21 dpi. The correlations found suggest that the measurement of Hp and CRP in saliva and meat juice could serve as complementary, or possibly alternative, biomarkers of pig herd-health.