Hydroxyproline and starch consumption and urinary supersaturation with calcium oxalate in cats

Abstract The effect of extruded foods intake with different contents of starch, protein and hydroxyproline were evaluated on water balance, oxalate renal excretion, urine chemical composition and the relative urine supersaturation with calcium oxalate (RSSCaOx) in cats. Three complete and balanced diets were formulated with different proportions of starch, protein and hydroxyproline: STARCH, high starch and low protein and hydroxyproline content diet; SOY, high protein and low hydroxyproline and starch content diet; HYDROX, high hydroxyproline and protein, and low starch content diet. Twenty-four cats were used, with 8 replicate cats per diet. Animals were submitted to an adaptation period of 10 days, followed by 7 days for total feces and urine collection and 1 day for blood collection. Data were submitted to analysis of variance and means compared by Tukey’s test (P