Dietary NaCl Does Not Affect Blood Pressure in Healthy Cats

Abstract

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.

Plasma Renin Activity and Aldosterone Concentrations in Hypertensive Cats with and without Azotemia and in Response to Treatment with Amlodipine Besylate

“…Assessment of glomerular filtration rate (GFR) could be useful to assist in clarifying this, but still would not exclude the possibility of hyperfiltration occurring in a decreased number of nephrons. Changes in sodium intake can influence volume status and BP, although evidence to support this in cats is limited 38, 39. In this study, the majority of cats were eating commercially produced diets, although the brands varied widely.…”

“…Similar to hypertensive black patients, cats demonstrate a limited antihypertensive response to ACEi therapy, but respond well to calcium channel blockade 7, 12. However, studies that have investigated the effect of sodium intake on SBP and renal function in cats have not reported an association 36, 37, 38, 39. Additional work is warranted to evaluate salt sensitivity in naturally occurring hypertension in cats and the role of angiotensinogen in cats with variable BP and renal function.…”

“…Changes in sodium intake can influence volume status and BP, although evidence to support this in cats is limited. 38,39 In this study, the majority of cats were eating commercially produced diets, although the brands varied widely. Therefore, sodium intake may have varied, but consumption of renal diets (which are often low in sodium) was an exclusion criterion.…”

Sodium in feline nutrition

“…Five studies reported the effects of various sodium intake levels on blood pressure in cats (Table ). In a randomized crossover study with 10 healthy young adult cats fed 620 mg/MJ ME sodium over 14 days, no differences in systolic blood pressure (measured via Doppler) were found vs. a diet of 285 mg/MJ ME sodium in the same cats (Luckschander et al., ). Moreover, Kirk et al.…”

Effects of Dietary Salt Intake on Renal Function: A 2‐Year Study in Healthy Aged Cats

“…Increasing urine volume, dilution, or both can be reliably achieved in healthy cats by feeding a dry diet with an increased content of salt , , . Appropriately designed dry diets with an increased salt content are able to dissolve naturally occuring struvite stones with a decrease or at least no change in the risk of calcium oxalate crystals formation , , .…”