EFFECTS OF DIFFERENT ZINC SALTS ON THE FE CAL AND RENAL EXCRETION OF ZINC AND ON ZINC CONCENTRATIONS IN THE BLOOD OF DOGS AND CATS

Net absorption, renal excretion and retention of zinc were investigate d in 4 adults dogs and 5 cats after feeding of a commercial dry food, supplemented with zinc sulphate or acetate in 2 doses (aimed were 2 an d 4 mg zinc per kg BW/d). Zinc concentrations were determined in the p lasma as well as the activity of alkaline phosphates. Following result s were obtained: Net absorption of zinc was highly variable (2-28% of intake), with higher values (n.s.) after feeding of the organic zinc a cetate (21/28% in dogs/cats) compared to zinc sulphate (15/2% in dogs/ cats). Retention of zinc was higher in dogs and cats after feeding the organic zinc supplement (1.4 vs. 1 mg/kg BW/d in dogs, 1.1 vs. 0.1 mg /kg BW/d in cats). Renal excretion of zinc remained on a constant leve l, independent of the dosage (dog: 0.04, cat: 0.01-0.02 mg/kg BW/d). Z inc concentrations in the plasma increased during zinc supplementation . In the control period in dogs 79, in cats 69 mug/dl were found, afte r addition of zinc in the highest dosage 110 resp. 114 mug/dl. The act ivity of alkaline phosphatase was not influenced by the Zn-supplementa tion. With regards to practical aspects in cases of dermatoses the ino rganic zinc salt may be as effective as the organic supplement if the dosage is in the usual range (2 mg zinc per kg BW/d), so under economi c aspects the use of zinc sulphate is possible.