title: Evaluation of sodium bisulphate and phosphoric acid as urine acidifiers for cats.
abstract: Eighteen cats were used to compare the urine acidifying properties of sodium bisulphate to phosphoric acid. Acidifying agents were added at one of three concentrations (0.4, 0.6, or 0.8%, as-is basis). Cats were offered a commercial diet to determine basal urinary pH, and then again for a 1 week period between blocks 1 and 2. Cats were acclimated to the diets for 6 days, and urine samples were collected on day 7 at 0, 4, and 8 h postfeeding to obtain pre- and postprandial urinary pH. Intakes of diets containing sodium bisulphate tended (P < 0.07) to be lower than intakes of diets containing phosphoric acid. Cats consuming the 0.8% phosphoric acid diet had higher (P < 0.05) food intakes than cats consuming either the 0.4 or 0.6% phosphoric acid-containing diets. There was significant (P = 0.01) linear and quadratic response for food intake in cats consuming the sodium bisulphate-containing diet. Cats consuming the 0.4 and 0.8% phosphoric acid-containing diets tended (P = 0.07) to have higher water intakes than cats consuming the 0.6% phosphoric acid-containing diet. There were no differences (P > 0.05) in urine pH and specific gravity between cats fed the different acidifier types. Cats consuming the 0.6% phosphoric acid-containing diet tended (P = 0.07) to have a higher urine pH 8 h post-feeding than cats consuming the 0.4 and 0.8% phosphoric acid-containing diets. Urine pH was highest at 4 h post-feeding except for cats fed the 0.4% sodium bisulphate- and the 0.6% phosphoric acid-containing diets. No differences (P > 0.05) between acidifiers were found in faecal score or in faecal dry matter and organic matter concentrations. A quadratic response was detected in faecal score for cats consuming the phosphoric acid-containing diets. Cats consuming the 0.6% phosphoric acid diet tended (P = 0.06) to have a lower faecal score than cats consuming the 0.4 and 0.8% phosphoric acid diets. For faecal dry matter, a linear trend was detected in cats consuming the sodium bisulphate (P = 0.08) and phosphoric acid-containing (P = 0.04) diets. Sodium bisulphate and phosphoric acid generally behaved in a similar fashion when incorporated in dry cat diets.
authors: Department of Animal Sciences, University of Illinois, Urbana, IL, USA.
authors: Julie K
authors: JK
authors: Spears
authors: Christine M
authors: CM
authors: Grieshop
authors: G C
authors: GC
authors: Fahey
mesh_terms: D000136:Acid-Base Equilibrium / Q000187:drug effects*; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002371:Cat Diseases / Q000517:prevention & control / Q000652:urine*; D002415:Cats / Q000652:urine*; D004305:Dose-Response Relationship, Drug; D004326:Drinking; D005243:Feces / Q000737:chemistry; D005260:Female; D006863:Hydrogen-Ion Concentration; D010756:Phosphoric Acids / Q000008:administration & dosage / Q000652:urine*; D011897:Random Allocation; D013431:Sulfates / Q000008:administration & dosage / Q000652:urine*; D014545:Urinary Calculi / Q000517:prevention & control / Q000652:urine / Q000662:veterinary*
chemical_list: D010756:Phosphoric Acids; D013431:Sulfates; C012036:sodium sulfate; C030242:phosphoric acid