Evaluation of Decreased Kidney Function in Dogs Receiving Carboplatin: A Retrospective Cohort Study of 98 Dogs (2006-2024).

Decreased kidney function is observed in some people receiving carboplatin, but limited literature explores this in dogs. The aim of this study was to evaluate the incidence and risk factors for decreased kidney function in dogs receiving carboplatin. A single-institute retrospective cohort study compared the incidence of decreased kidney function between non-azotaemic dogs receiving carboplatin and an age- and weight-matched cancer-bearing control group not receiving chemotherapy. Change in creatinine concentration and a linear mixed effects model were used to compare trends in creatinine between groups. Decreased kidney function was defined as a sustained increase in creatinine ≥ 26.5 μmol/L on ≥ 2 consecutive measurements compared to baseline; the VCOG-CTCAE v2 grading system for increased creatinine was also applied. Risk factors were explored. Ninety-eight dogs were included (n = 49/group). There was no difference in median change in creatinine concentration (+2.0 μmol/L; p = 0.311) or creatinine trends (p = 0.958) across the study period between groups. Incidence of decreased kidney function was low and did not significantly differ between groups (carboplatin group n = 4 [8.2%]; control group n = 2 [4.1%]; p = 0.678); no risk factors were identified. There was no difference in the frequency of VCOG grade one (p = 0.731), two (p = 0.641) or three (p = 0.429) creatinine adverse events between groups. Non-azotaemic dogs receiving carboplatin do not have a significantly increased short-term risk of decreased kidney function compared to those not receiving chemotherapy, although the numerical increase in incidence in dogs receiving carboplatin could be clinically relevant. Larger studies should aim to explore this further and investigate carboplatin's impact on subclinical and long-term renal function.