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.