The positive correlation between serum MCP-1 and CRP has already been described in dogs in various inflammatory diseases, such as inflammatory bowel disease, immune-mediated hemolytic anemia, thrombocytopenia purpura, eosinophilic pneumonia, immune-mediated arthritis, glomerular nephritis, pancreatitis, and panniculitis, in a previous study [27]. Here, CCL2 is linked to eosinophilic pneumonia.