Acute B. canis infection can lead to an acute phase reaction (APR) in dogs. The parasite invades red blood cells causing anemia through immune-mediated hemolysis and possible erythropoietic suppression. A regenerative response of the erythroid lineage during the babesiosis has not been described in extension. This research examines hematologic parameters focusing on the absolute reticulocyte count and apolipoprotein A I (ApoA I) level on the day of admission and 14 days after treatment with imidocarb-dipropionate in young (n=11) and adult (n=11) dogs naturally infected with B. canis. Metabolic and inflammatory processes were characterized by analyzing protein and lipid profiles, as well as ApoA I at specified time points. Automated analyzers were used to determine complete blood count and biochemical parameters, while ApoA I was assessed using radioimmunoassay. The reticulocyte count was determined using a manual method by means of supravital staining. Both young and adult dogs with acute B. canis infection showed non-regenerative anemia without difference. Fourteen days after successful treatment with imidocarb-dipropionate, the anemia was corrected and a high reticulocyte count was observed (p<0.05). This indicates that the erythroid regenerative response was efficient in young and adult dogs, although vital signs, leukocyte count and triglyceride concentration suggest a more intense APR in young dogs. A decrease in ApoA I in both groups 14 days after treatment (p<0.01) confirmed that this lipoprotein acts as a positive acute-phase protein in acute B. canis infection in dogs, but further studies are needed to connect its role in erythroid lineage regeneration.
