Association of proteinuria at time of diagnosis with survival times in dogs with lymphoma

Abstract Background Lymphoma has been implicated as a possible cause of proteinuria in dogs. However, information about the potential importance of proteinuria in dogs with lymphoma is limited. Hypothesis To determine if the presence of proteinuria at diagnosis was associated with median survival times in dogs with lymphoma and if lymphoma stage (I‐V) or type (B vs T) were associated with the presence of proteinuria. Animals Eighty‐six client‐owned dogs with a new diagnosis of lymphoma between 2008 and 2020. Methods This was a retrospective cross‐sectional study with dogs divided into proteinuric or nonproteinuric groups based on dipstick urine protein (protein ≥30 mg/dL classified as proteinuric) or a ratio of dipstick protein to urine specific gravity (ratio ≥1.5 classified as proteinuric). Dogs were excluded for: (1) treatment within 2 months with glucocorticoid, anti‐neoplastic, or anti‐proteinuric therapies, (2) diagnosed hypercortisolism or renal lymphoma, (3) active urine sediment, or (4) urine pH >8. Survival analysis utilized a Kaplan‐Meier estimator and log‐rank testing. Results There was a significant difference in median survival between proteinuric and nonproteinuric dogs classified by urine dipstick (245 days [91, 399] vs 335 days [214, 456]; P = .03) or UP : USG (237 days [158, 306] vs 304 days [173, 434]; P = .03). No difference in prevalence of proteinuria was identified between stages (I‐V) or types (B and T). Conclusions and Clinical Importance Proteinuria appears to be negatively associated with survival time in dogs newly diagnosed with lymphoma.