Aim: This study was conducted to evaluate the possible association between values of certain serum biochemical parameters and seropositivity against Anaplasma marginale in dairy cows.

Materials and Methods: Serum samples from 60 seropositive and 40 seronegative cows were used to determine the values of beta-hydroxybutyrate (BHB), glucose, creatinine, blood urea nitrogen, total protein, albumin, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), and gamma-glutamyl transferase (GGT) using commercially available kits and reagents. The serostatus of cows against A. marginale was determined using a commercially available cellular enzyme-linked immunosorbent assay kit according to the manufacturer's recommendations. Significant differences in serum biochemical values between seropositive and seronegative groups were evaluated using independent Student's t-test. Possible associations between the serostatus of the cows and different biochemical parameters were evaluated using univariate followed by multivariate logistic regression analyses.

Results: There was a statistically significant increase (p≤0.05) in values of total protein, BHB, LDH, and AST in seropositive cows compared to seronegative cows while a non-significant increase in values of ALP, ALT, and GGT was detected in seropositive cows. A strong correlation (R=0.69) between serum levels of BHB, LDH, and AST and seropositivity against A. marginale was detected.

Conclusion: There is evidence of a possible association between A. marginale infection and liver damage/hepatic fatty degeneration in dairy cows. Further studies, however, are required to elucidate the exact pathophysiological mechanisms of this relationship.

Keywords: blood parasites, dairy cows, hemolysis, metabolic diseases.