Clinical findings, prognostic factors, and outcome of protein‐losing nephropathy in cats: A retrospective study

Abstract Background Primary glomerular disease resulting in protein‐losing nephropathy (PLN) is an uncommon cause of chronic kidney disease in cats, yet is important to recognize because it warrants specific treatment that impacts outcome. Hypothesis/Objective Characterize clinicopathologic findings, prognostic indicators, and short‐ (≤30 days) and long‐term survival of cats with PLN. Animals Thirty‐seven cats with naturally occurring PLN. Methods Medical records of cats with PLN admitted to a veterinary teaching hospital were retrospectively reviewed. Results Median age was 3 years (range, 1.5‐11.5 years) and 17/37 (46%) were males. Short‐term survival was 57%. The estimated median survival time of all cats was 424 days (95% confidence interval [CI], 0‐1098 days). Common clinical signs included lethargy (57%), edema (46%) and weight loss (35%). Edema was more common in short‐term survivors compared with nonsurvivors (odds ratio [OR], 0.21; 95% CI, 0.05‐0.86‐20.4; P = .04). Serum creatinine concentration at presentation was negatively associated with long‐term survival (OR, 1.3; 95% CI, 1.03‐1.52; P = .01). Administration of immunosuppressive and antiproteinuric medications was more common among short‐term survivors compared with nonsurvivors (18/20 [90%] vs 9/16 [56%]; OR, 7.0; 95% CI, 1.2‐40.8; P = .05 and 17/20 [85%] vs 7/16 [44%]; OR, 7.3; 95% CI, 1.5‐35.2; P = .01, respectively). Partial or complete remission was documented in 11/31 (36%) cats and was associated with both short (OR, 3.3; 95% CI, 1.7‐6.5; P < .001) and long‐term survival (P = .003). Conclusion and Clinical Importance Cats with PLN have a guarded prognosis, but achieving remission improves outcome. Cats presented with edema rather than azotemia are more likely to respond to treatment.