Dietary NaCl does not affect blood pressure in healthy cats

The purpose of this study was to assess the effects of dietary salt intake on systolic blood pressure, water intake, urine output, and urine concentration in cats. Ten healthy young adult cats (mean age 2.5 years) were randomly divided into 2 groups and fed either a control diet (0.46% Na and 1.33% Cl on a dry matter [DM] basis) or a diet with a moderately increased salt content (1.02% Na and 2.02% Cl on a DM basis) for 2 weeks. After a 1-week wash-out period, each group was switched to the opposite diet for 2 weeks. During each 2-week study period, food and water intake, urine volume, urine specific gravity, and urine osmolality were measured daily. Systolic blood pressure (calculated as the mean of 5 readings measured with a Doppler flow detector) was assessed twice daily. No significant effect of diet composition was found on systolic blood pressure, and blood pressure measurements remained within reference limits throughout the study in all 10 cats. However, animals fed the higher salt diet had significantly increased water intake and urine osmolality, and significantly decreased urine specific gravity in comparison to animals fed the control diet. Examination of results of this preliminary study suggests that feeding a diet with moderately increased salt content increases water intake and causes diuresis without increasing systolic blood pressure in healthy adult young cats.