Evaluation of clinical, hematological and biochemical parameters with cystatin C in cats with renal damage

Chronic kidney disease (CKD) is a common, progressive, and irreversible condition in aging cats. Therefore, early detection of renal dysfunction is essential for slowing disease progression and improving quality of life. Traditional biomarkers such as creatinine and blood urea nitrogen (BUN) tend to increase only after significant nephron loss, highlighting the need for more sensitive and earlier indicators. In this context, Cystatin C has emerged as a promising biomarker that may reflect glomerular filtration rate (GFR) more accurately in the early stages of renal impairment. This study aimed to evaluate the potential role of serum Cystatin C in the early diagnosis of kidney dysfunction in cats diagnosed with CKD. A total of 25 cats of different breeds and ages were included. Following a general clinical examination, hematological and biochemical parameters were analyzed. Serum Cystatin C levels were measured using a quantitative immunofluorescence assay, and the data were evaluated statistically. According to the biochemical results, the average creatinine level was 4.49 mg/dL, BUN was 80.62 mg/dL, and Cystatin C level was 14.72 mg/dL. A statistically significant correlation was found between Cystatin C levels and both creatinine and BUN concentrations (p<0.05). These findings suggest that Cystatin C may serve as a valuable biomarker for the early detection of renal dysfunction. Moreover, common clinical symptoms observed in the cats included weight loss, dehydration, vomiting, and polyuria. In conclusion, monitoring serum Cystatin C levels may contribute to the early diagnosis of CKD in cats. However, using Cystatin C in conjunction with other parameters is recommended for more accurate evaluation. Further studies with larger sample sizes are necessary to establish its clinical utility more definitively.