<p>Under conditions of dietary sodium (Na⁺) excess, the kidneys may fail to adequately excrete Na⁺, potentially compromising blood pressure homeostasis. Body tissues, such as skin, can offer sites of short-term extrarenal Na⁺ storage and previous research has shown that this can help guard against hypertension in small mammals (e.g., rodents). Large mammals have relatively greater Na⁺ storage potential, but whether extrarenal Na⁺ storage occurs for this group is unknown. Here, we report preliminary evidence of extrarenal Na⁺ storage in cattle. We provided a large pulse-dose of NaCl to four cattle (body mass: ~720&#xa0;kg) and measured excretion of Na⁺ and potassium (K⁺) in urine and faeces for a period of 7-days. Following NaCl administration, Na⁺ excretion spiked in both urine and faeces for ~ 48&#xa0;h before returning to baseline measurements. After ~ 96&#xa0;h, however, Na⁺ excretion increased again; a consistent physiological phenomenon across all individuals studied. We did not observe a pattern in urinary K⁺ excretion, indicating that the mechanism of Na⁺ storage does not appear to involve exchange for K⁺. However, faecal K⁺ excretion was reciprocal to that of Na⁺, presumably reflecting exchange of Na⁺/K⁺ across the walls of the large intestine. We infer that during the initial period of Na⁺ stress, short-term extrarenal Na⁺ storage occurred and the stored Na⁺ was later released only when the body had returned to Na⁺ homeostasis. Additional experiments are required to understand how patterns of Na⁺ regulation changes across body sizes and the specific body compartments involved. Cattle may be a useful model system for examining the impact of high Na⁺ intake in mammals larger than humans.</p>