Absence of a salt (NaCl) preference or appetite in sodium-replete or depleted kittens

Many omnivores and herbivores exhibit an appetite for sodium or salt (NaCl) solutions, but a similar sodium appetite has not been demonstrated in carnivores. The choice for or against sodium-adequate diets of sodium-replete and depleted kittens (confirmed by an elevated plasma aldosterone concentration) was examined using a two-bowl choice test. Both bowls contained purified diets, one bowl with one of various levels of sodium (as NaCl) and the other bowl a sodium-deficient diet (0.1g Na/Kg). Neither sodium-replete nor depleted kittens showed a choice of the diet containing 2g Na/kg over the deficient diet. Both groups of kittens showed significant aversion to a diet containing 10g Na/kg diet, with no change in total food intake. Kittens previously exposed to a diet containing 10g Na/kg diet appeared to have a learned aversion to sodium in subsequent choice tests. We conclude that kittens do not possess an innate sodium appetite and that a sodium appetite is not induced in sodium-depleted kittens.