Retrospective Study of 1,098 Blood Samples with Anemia from Adult Cats: Frequency, Classification, and Association with Serum Creatinine Concentration

BACKGROUND: Frequency and classification of anemia in terms of regeneration status and erythrocyte indices are not well described in cats. OBJECTIVE: To determine frequency and regenerative status of anemia in samples from adult cats, to assess the sensitivity and specificity of macrocytosis and hypochromasia for detecting regenerative anemia (RA), and to evaluate the association of anemia with increased serum creatinine concentration (SC). STUDY POPULATION: Laboratory records from 30,503 blood samples from cats (2003–2011). METHODS: Clinicopathologic data reviewed retrospectively. Anemia defined as hematocrit (Ht) ≤27%, red blood cell count (RBC) ≤5.5 × 10⁶/μL and hemoglobin (Hb) ≤9.0 g/dL. RA defined by manual absolute reticulocyte count >50 × 10³/μL. Macrocytosis was defined as mean corpuscular volume (MCV) >55 fL and hypochromasia as mean corpuscular hemoglobin concentration (MCHC)