Chloride requirement of kittens for growth is less than current recommendations

The minimal chlorine (chloride) requirement of kittens for growth was deter mined in a study in which kittens were given purified diets containing 0.1, 0.4, 0.7, 1.0 or 1.3 g of chloride (CI) as KCl/kg diet. Each dietary group contained six (three males and three females) specific-pathogen-free kitte ns; the diets were fed for 30 d. Kittens receiving diets with <0.7 g Cl/kg became alkalotic as evidenced by an increase in blood pH, blood bicarbonate , standard bicarbonate, actual base excess, standard base excess, partial p ressure of carbon dioxide (pCO(2), and total CO2. In addition, kittens were hypochloremic and hypokalemic; they had decreased serum ionized calcium an d a negative chloride balance. On the basis of the chloride balance measure ments, a broken-line nonlinear least-square analysis predicted a CI require ment as 0.89 g Cl/kg diet (22 kJ/g diet). Because the dietary CI concentrat ion closest to 0.89 g/kg that we tested was 1.0 g Cl/kg, we recommend a min imum chloride requirement of 1.0 g Cl/kg diet for growing kittens. This val ue is considerably less than the recommended chloride requirement of the Na tional Research Council of 1.9 g Cl/kg diet, or the allowance of the Associ ation of American Feed Control Officials of 3.0 g Cl/kg diet. Because the b ioavailability of chloride is high, the previous estimates appear excessive .