Detection of IgG, IgM or C3 on erythrocytes via direct antiglobulin test (direct Coombs test); measurement of WBC, RBC, HGB, HCT, MCV, MCH, MCHC, RDW, reticulocytes, PLT, PCT, MPV; and microscopic blood smear review for WBC differential, cellular morphology, and hemoparasites. A positive Coombs can support the diagnosis of immune-mediated hemolytic anemia (IMHA) when compatible clinical and CBC findings are present.