Evidence of acute phase reaction in asymptomatic dogs naturally infected with Babesia canis

[Display omitted] •Increased serum amyloid A and total proteins mark dysproteinaemia.•Higher dominant α-lipoproteins’ diameter indicates the associated dyslipidaemia.•Lower paraoxonase-1 indicates oxidative stress.•In contrast to overt babesiosis, leukocyte count is close the upper reference limit. Asymptomatic outdoor dogs can be carriers of Babesia canis, but data describing the development of an acute phase response (APR) are not available. We hypothesised that these dogs have a moderate APR that could be detected by hematological and biochemical changes. Two groups of Babesia-exposed dogs were represented by nine B. canis PCR-positive and twenty B. canis PCR-negative, seroreactive dogs. The control group consisted of ten Babesia-naïve dogs. Serum amyloid A (SAA), paraoxonase-1 (PON-1), complete blood count, and biochemistry parameters were analysed by standard methodologies. Protein and lipoprotein fractions were separated using agarose gel electrophoresis (GE), and the dominant diameters of lipoproteins were assessed on gradient GE. Results were evaluated using non-parametric tests and the Receiver Operating Characteristic curve. SAA (median 39.0 μg/mL, range 2.2–48.8 μg/mL), total protein (median 74.7 g/L, range 57.1–98.3 g/L) and the dominant diameter of α-lipoproteins (median 13.31 nm, range 12.09–14.17 nm) in B. canis PCR-positive dogs were higher relative to dogs in the control group or dogs that were PCR-negative but seroreactive (p