Abstract: Background- Hypoalbuminemia (HA) has been associated with morbidity and mortality in people. Little is known about the occurrence of hypoalbuminemia in cats and its impact on survival. Hypothesis/Objectives- To describe the characteristics of cats presenting with moderate (albumin 2-2.5 g/dL) or severe (albumin < 2 g/dL) HA and compare their survival rates to cats without HA (albumin > 2.9 g/dL). Animals-291 cats with HA and 291 age- and breed-matched control cats.Methods- Retrospective case-control study (2018-2023). Clinical data and outcome were reviewed. Duration of hospitalization was compared using a Mann-Whitney U test. Short- and Long-term survival rates were analyzed with Kaplan-Meier survival analysis accompanied by the log-rank test and the restricted survival mean time (RMST). Results- Of the 2927 cats that had a plasma albumin measured, 200 (6.8%) had moderate HA and 91 (3.1%) had severe HA. The most common disease processes associated with HA were infectious disease (34% HA, 14% controls) and neoplasia (22% HA, 10% controls). Duration of hospitalization was significantly longer in cats with HA compared to controls (median 2 [Interquartile range, IQR: 1-4] days, median 2 [IQR: 1-3] days, respectively; p < 0.0001). Cats with HA had lower short-term and long-term survival rates compared to controls (p < 0.0001 for both, Figures 1-2). The RMST for cats with severe HA (418 days, p = 0.0003) and moderate HA (638 days; p < 0.0001) were significantly less than that of controls (881 days). Conclusions and clinical importance- Hypoalbuminemia is a clinically relevant negative prognostic indicator in cats.
