Seasonal differences in the intensity of acute phase response in dogs infected with Babesia canis

The highest number of acute Babesia canis cases in dogs is recorded over the February-May (Feb-May) period, which also represents the optimal climate conditions for tick activity in Belgrade, Serbia. A possibility that the acute phase response is more intense in dogs developing the disease in the Feb-May period compared with the response in other time periods of the year was tested. A total of 63 client-owned dogs with acute B. canis infection were enrolled and the routine hematology and biochemistry parameters-serum amyloid A (SAA), IgG against B. canis, level of parasitemia, ceruloplasmin (CER), paraoxonase-1 (PON-1), and fibrinogen-were measured. Acute phase indexes (API) were calculated as (SAA×CER)/(Iron×PON-1) and (SAA×CER)/(Albumin×Iron). Statistics included Kruskal-Wallis test and logistic regression analysis. The results showed that in the Feb-May period, the following parameters were lower: creatinine, albumin, iron, and level of parasitemia. Furthermore, increased API values were more probable in the Feb-May than in the other periods. Together, higher acute phase response intensity and presumptive hemodilution in the Feb-May period indicate a more acute course of B. canis infection than in other time periods of the year.