RESEARCH NOTES: Prediction of urine pH in cats fed dry and wet foods
Petfood Industry Newsletter, August 15, 2006
Vol. 6, No. 16
The objective of this study was to determine if urine pH can be predicted using the nutrient components of feline foods. One hundred fifty foods (90 dry foods, 60 wet foods) were fed to groups of 10 adult cats (mean, 8.5 years of age) to determine the urine pH of cats fed each food. The food was fed for a period of 7 days, and pH was determined on freshly-voided urine on days 5 to 7 of the test. Through step-wise regression, it was determined which cations, anions and sulfur-containing amino acids were of importance for urine pH prediction.
Three models were developed for urine pH prediction. These models included: 1) wet and dry foods; 2) wet only foods; and 3) dry only foods. The cations included in all models were sodium, potassium and magnesium. Calcium was excluded from the wet only model. The anions for all models were chloride, sulfur and phosphorus. Including sulfur in the model allowed for the exclusion of methionine and cysteine from the dry model.
Urine pH of adult cats can be predicted from the nutrient components of the food, thus reducing the number of animal studies in order to optimize urine pH (for struvite and/or oxalate prevention) for specific products. Separate formulas must be used for dry and wet foods in order to maintain accuracy.
Source: Yamka, R.M., Friesen, K.G. and Schakenraad, H., 2006. The prediction of urine pH using dietary cations and anions in cats fed dry and wet foods. Intern J Appl Res Vet Med 4(1):58-66.