Different sources of sulfur in diets of adult cats on the urinary parameters and acid-base balance

Abstract

Urolithiasis is a common disorder in the veterinary clinic and is considered as one of the most frequently cause of morbidity. This disorder is closely associated with urinary pH and nutrition plays a key role in the control of this disease, because through dietary manipulation it is possible to modify the urinary pH. Sulfur is considered macroelement with a strong influence on the acid-base status and may be crucial to control urinary pH in cats. The purpose of this study was to evaluate the effects of addition of different sources of sulfur (S) in the diet of cats on the urinary parameters and acid-base balance. Forty-two healthy adult cats were divided into 3 groups, and each group of 14 cats received 7 diets in a complete randomized block design. Calcium sulfate (CaSO4), DL-methionine (DLM) and methionine hydroxy analog (MHA) were added to a control diet in two levels (1.28g S/kg and 2.56g S/kg) to formulate 6 other experimental diets. The acid-base balance was evaluated by hemogasometry in samples of venous blood. The DLM at the highest level and MHA differed of the control diet in relation to urinary pH (P<0.05). Calcium sulfate; although, not differentiated from the control diet, has been shown to alter urinary pH despite its zero electrolyte balance. Apparently, the alkalizing effect of calcium was not sufficient to avoid sulfate acidification of the urine. Treatments showed no alteration of the acid-base balance of the animals and no affect the consumption of the diets.

Case Report: Application and Limitations of a Plant-Based Diet Formulated for a Cat With Feline Lower Urinary Tract Disease

“…As with the commercial diets, appropriate dietary protein, sulfur amino acids, EPA+DHA, and salt, and lower magnesium were prioritized. Reduction of urine pH was anticipated by manipulating the base excess of the diet and including sulfur-rich acidifying ingredients (12), while increased urine production was expected by increasing salt and recommendations to add water to the food and stimulate voluntary water intake. Initially, the cat's acceptance of the homemade diet formulated by the nutrition service was also limited, and the owner reported inappetence or disinterest in eating the diet.…”

“…The cat was re-presented to the Clinical Nutrition Service, weighing 5.8 kg with a BCS of 6 on a 9-point scale. A homemade plant-based diet was designed using web-based formulation software 1 (Tables 3, 4) to meet the AAFCO nutrient profile for adult maintenance with low concentrations of struvite precursors, and utilized ingredients intended to promote urine acidity (12). Acidification of the urine was predicted by calculation of the base excess of the diet (13).…”