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Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616
The sodium requirement of adult cats for maintenance was determined
using a randomized block design of eight dietary sodium treatments
(0.1, 0.4, 0.5, 0.66, 0.8, 1.2, 1.6 or 2.0 g Na/kg in a
caseinlactalbumin-based purified diet) administered for periods of 4
wk. A total of 35 adult specific-pathogen-free domestic shorthaired
cats (26 males and 9 females, 1.53 y of age) was given an
equilibration diet (2 g Na/kg) for 14 d before assignment (or
reassignment) to the treatments. A total of 12 cats (8 males, 4
females) was randomly assigned to the lowest six levels of sodium, and
four cats to the highest two sodium levels. Cats consuming the diet
containing 0.1 g Na/kg had significantly elevated aldosterone
concentration in plasma, and packed cell volume. In addition, these
cats exhibited anorexia, body weight loss, reduced urinary specific
gravity and sodium excretion, and had a negative sodium balance.
However, adult cats did not develop polydypsia and polyuria reported in
sodium-deficient kittens. Cats given the diet containing 0.66 g
Na/kg did not have an increased packed cell volume, but aldosterone
concentration in the plasma was significantly elevated. However, cats
given diets containing
0.8 g Na/kg had plasma aldosterone
concentrations
0.7 nmol/L (reference value for sodium-replete cats)
and normal packed-cell volumes. A minimal sodium requirement of adult
cats for maintenance of 0.8 g Na/kg diet (energy density = 22
kJ/g diet) or 0.4 mmol Na · kg body weight-1 · d-1 is proposed.
KEY WORDS: cats sodium aldosterone requirement