Evaluation of fetal heart serum amyloid a concentrations in infectious cattle abortion cases

Serum amyloid A (SAA) concentrations have been investigated in diseases of human and domestic animals and increased SAA levels have been reported in infectious diseases. In the present study, we determined the fetal heart blood SAA concentrations in aborted bovine fetuses and investigated the relationship between the level of SAA and causative infectious agents. A total of 46 heart blood samples were collected from aborted bovine fetuses between July 2018 and July 2019 and were assigned to two groups according to microbiological, pathological and molecular results. Group 1: An infectious disease was diagnosed by detecting a microorganism (21 cases); Group 2: An infectious or inflammatory disease was not detected (25 cases). The fetal heart blood SAA concentrations were measured by commercial ELISA test. Serum amyloid A concentrations in aborted bovine fetuses were elevated from 6.1 to ≥40 mg/L in 17 of 21 cases in group 1. In group 2, SAA concentrations were less than 2.5 mg/L in 23 of 25 cases. This difference was statistically significant between group 1 and group 2. These findings suggest that SAA concentrations in fetal heart blood from bovine fetuses is potentially a novel marker for distinguishing between infectious and non-infectious bovine abortion cases.