Inflammatory Status and Chronic Kidney Disease in Cats: Old and New Inflammatory Markers—A Pilot Prospective Study

This prospective study aimed to evaluate inflammatory status in cats affected by chronic kidney disease (CKD) at IRIS stages 2–4, using serum amyloid A (SAA) and the erythrocyte sedimentation rate (ESR) as inflammatory markers. Thirty-two cats with CKD and ten clinically healthy cats (i.e., control group) were enrolled. The recording of signalment data, complete physical examinations, and abdominal ultrasonography were performed for each animal. Additionally, ESR levels, complete blood count, clinical chemistry (including SAA determination), serum protein electrophoresis, and complete urinalysis were executed. This study’s results showed that mean ESR and SAA concentrations in cats with CKD were statistically higher compared to those of the control group (p = 0.0005 and p = 0.007, respectively). The SAA concentration was significantly increased at IRIS stages 2, 3, and 4 compared to the control group. Meanwhile, the ESR was significantly higher in cats at IRIS stages 3 and 4 (p = 0.0003 and p = 0.0007, respectively), but not at IRIS stage 2, compared to the control group. These results provide evidence that feline CKD is associated with a systemic inflammatory status. Moreover, the rise in ESR appears to be more linked to advanced stages of the disease and could, therefore, correlate with the uremic condition.