Chronic kidney disease (CKD) is increasingly common in older cats. The transforming growth factor-beta (TGF-β) pathway is associated with renal fibrosis. This study aimed to quantify the mRNA expression of TGFβ, MAPK, and Bcl2 genes and the protein expression of TGF-β and MAPK in feline kidney cells and tissues. Gene expression analysis was conducted using relative gene expression, while protein expression was assessed through western blot analysis. The immunohistochemistry staining of TGF-β and MAPK was performed on feline kidney tissues. The result reveals the significant upregulation of TGFβ (P = 0.001) and considerable downregulation of Bcl2 (P = 0.010) in doxorubicin-treated feline kidney cells. Protein expression level of TGF-β and MAPK also tended to increase in doxorubicin-induced feline kidney cells. The immunostaining levels of TGF-β and MAPK were higher in the kidney tissues of cats with CKD compared to the no lesions group. A deeper understanding of the TGF-β pathway could enable veterinarians to monitor disease progression and mitigate complications in feline CKD.