Objectives: The aim of the study was to evaluate the effects of oral administration of clinical dose of beraprost for feline CKD in healthy cats, and also to examine whether NOS inhibition reversed them. Methods: A placebo-controlled pharmacological sequential design study was carried out to assess plasma aldosterone and renin concentrations, mean blood pressure, heart rate, renal plasma flow, and renal vascular resistance. Results: Beraprost reduced plasma aldosterone when compared to the placebo (P < 0.05); this was reversed when NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME) was added to beraprost treatment (P < 0.01). No differences in the plasma renin concentration or hemodynamic parameters were detected between beraprost and placebo. The correlation ratios (η2) showed opposite relationships between beraprost and added L-NAME effects on aldosterone concentration, mean blood pressure, heart rate, renal plasma flow, and renal vascular resistance (P < 0.001). Conclusions: In healthy cats, the clinical dose of beraprost suppresses plasma concentration of aldosterone, which can be reversed by inhibition of NOS.

Background: Overall survival is the most important outcome for treatment response in feline chronic kidney disease (CKD). Beraprost has been shown to reduce the kidney function decline in cats with International Renal Interest Society (IRIS) stage 2 and 3 CKD. However, association with prolonged survival has not yet been examined. Objective: To assess the relationship between beraprost and overall survival in cats with CKD in real clinical practice. Animals: Client-owned cats with IRIS stage 3 CKD (n = 134), evaluated between 2017 and 2020. Methods: Retrospective cohort study based on data from electronic medical records of one hospital. Results: Multivariable Cox regression models on all treatment effects showed that beraprost only was related to better survival (P = 0.028). The cohort was divided into “beraprost therapy” and “no beraprost therapy” groups, and survival analyses revealed that overall survival was significantly longer in the beraprost therapy group, using Kaplan-Meier curves (P = 0.004). However, baseline phosphate is known to be an important prognostic indicator and was not well balanced between the two groups. Therefore, a subcohort of 97 cats was selected (those having baseline phosphate < 6.0 mg/dL) that allowed for this parameter to be balanced between groups. The survival data in this subcohort was consistent with that of the overall study cohort. Conclusions: In feline patients with CKD, beraprost therapy was associated with better overall survival.