Predictive factors associated with short-term mortality in cats with feline infectious peritonitis treated with remdesivir or GS-441524 or both.

Background: Although most cats with feline infectious peritonitis (FIP) respond to treatment with remdesivir or GS-441524 or both with uneventful clinical courses, some die despite treatment.

Objective: Identify predictive factors associated with short-term mortality in cats with FIP treated with IV remdesivir or PO GS-441524 or both.

Animals: A total of 108 client-owned cats with FIP.

Methods: Retrospective multicenter study using data collected from medical records. Factors associated with short-term mortality, defined as death within 84 days, were identified. Univariate analysis a t-test, Mann-Whitney U test, or Fisher's exact test and multivariate logistic regression were performed to assess patient characteristics and clinicopathological variables between survivors and nonsurvivors.

Results: The short-term mortality rate was 12.0% (95% confidence interval [CI], 6.6%-19.7%). Univariate analysis identified plasma lactate dehydrogenase activity (LDH; P < .001) and bilirubin concentration (P = .001) as being significantly increased in nonsurvivors, whereas concentrations of albumin (P = .003), total protein (P = .03), sodium (P = .005), and potassium (P = .005) were significantly lower. Additionally, nonsurvivors were significantly less likely to be febrile (≥39.4°C; P = .006). Of these variables, only plasma LDH activity ≥323 U/L, a cut-point determined by receiver operating characteristic curve analysis, was significantly associated with short-term mortality by multivariate analysis (odds ratio, 15.30; 95% CI, 1.18-198.00; P = .04).

Conclusion: Increased plasma LDH activity might be useful for predicting short-term mortality, guiding monitoring, and establishing prognosis in cats with FIP.