Chronic Kidney Disease in a Young Cat Associated With Congenital Kidney Defect

Chronic kidney disease (CKD) is one of the most relevant systemic diseases in feline clinical medicine, characterized by the progressive and irreversible loss of renal function. Although it is more frequently diagnosed in older animals, its occurrence in young patients has significant clinical importance, especially when associated with congenital structural alterations of the renal parenchyma. This study aimed to report a case of CKD diagnosed in a young, mixed-breed cat, 11 months old, seen during a routine home visit for pre-operative evaluation for elective castration. The disease was identified through the detection of persistent azotemia in serial laboratory tests, associated with ultrasonographic findings compatible with unilateral renal hypoplasia or dysplasia and contralateral compensatory hypertrophy. Clinical staging was performed according to the guidelines of the International Renal Interest Society (IRIS), classifying the patient as Stage 2, non-proteinuric, and normotensive. Nephroprotective management was instituted based on dietary adjustment, supplementation with omega-3 fatty acids, punctual use of phosphate binders, and serial clinical and laboratory monitoring. Over 16 months of follow-up, the patient maintained clinical and laboratory stability, with no evidence of significant disease progression. The case shows the relevance of early diagnostic investigation of renal alterations in felines, and follow-up for the implementation of individualized therapeutic strategies to maintain renal function. Keywords: Nephropathy. IRIS staging. Disease.