Study of nephrolithiasis and ureterolithiasis in cats with chronic kidney disease

Nephrolithiasis and/or ureterolithiasis were investigated by means of ultrasonography in 72 cats with chronic kidney disease (CKD), predominantly classified in stage II, according to IRIS - International Renal Interest Society criteria. Of these patients, 47 (65.27%) had nephrolithiasis and/or ureterolithiasis. There was no statistical difference between the study group (CKD with calculi) and control group (CKD without calculi) regarding age (p=0.274). Nevertheless, patients with nephrolithiasis and/or ureterolithiasis had greater evidence of renal injury, characterized by statistically significant differences in the urinary density (p=0.013) and the smaller size of the right kidney (p=0.009) and left kidney (p=0.048), measured in the longitudinal plane. There were no difference between groups in the other parameters investigated such as plasmatic total calcium, ionized calcium, phosphorus, sodium, potassium and intact parathyroid hormone concentrations. The values of serum urea and bicarbonate differ between groups with p=0.039 and p=0.037, respectively. Furthermore, arterial blood pressure was measured, remaining unchanged between the groups. One can conclude that nephrolithiasis and/or ureterolithiasis are common findings in cats with CKD and these results reinforce the need to perform image investigation in cats with CKD even in the asymptomatic ones, or those in the early stages of the disease.