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

Dóris Pereira Halfen,João Paulo Fernandes Santos,Juliana Toloi Jeremias,Luciano Trevizan,Thiago Henrique Annibale Vendramini,Fabio Alves Teixeira,Marcio Antonio Brunetto,Patricia Massae Oba,Alexandre De Mello Kessler,Aulus Cavalieri Carciofi

doi:10.1590/0103-8478cr20180017

Abstract

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.

Highlights

The macroelement composition of diets has a strong influence on the acid-base status and urinary pH of animals (KIENZLE et al, 1991; ALLEN & KRUGER, 2000; WAGNER et al, 2006).Treatment for urolithiasis in dogs and cats has been advent of new studies in the past century and as uroliths management is evolving, nutrition remains a subject of much clinical interest and debate in the management of these animals (LULICH et al, 2016) since the urine pH has strong influence on Approved 08.08.18 Returned CR-2018-0017.R2 by the authorRural, v.48, n.10, certain types of urolith formation (BARTGES & CALLENS, 2015; BARTGES, 2016).Struvite uroliths are associated with alkaline pH (LANGSTON et al, 2008)
Calcium sulfate, DLM, and Methionine hydroxy analog (MHA) were added at two levels, 1.28 and 2.56g S/ kg of diet, into a basal extruded dry cat food with base excess (BE) around 100mEq/kg, previously ground in a cutting mill equipped with a 1mm screen
Urine pH was affected by treatments, being significantly different between control diet experimental diets, with DLM 2.56g S/kg and MHA at both doses of sulfur (P

Summary

Introduction

The macroelement composition of diets has a strong influence on the acid-base status and urinary pH of animals (KIENZLE et al, 1991; ALLEN & KRUGER, 2000; WAGNER et al, 2006).Treatment for urolithiasis in dogs and cats has been advent of new studies in the past century and as uroliths management is evolving, nutrition remains a subject of much clinical interest and debate in the management of these animals (LULICH et al, 2016) since the urine pH has strong influence on Approved 08.08.18 Returned CR-2018-0017.R2 by the authorRural, v.48, n.10, certain types of urolith formation (BARTGES & CALLENS, 2015; BARTGES, 2016).Struvite uroliths are associated with alkaline pH (close to or greater than 7.0) (LANGSTON et al, 2008). The macroelement composition of diets has a strong influence on the acid-base status and urinary pH of animals (KIENZLE et al, 1991; ALLEN & KRUGER, 2000; WAGNER et al, 2006). Reduction of urinary pH has been shown to be effective in decreasing the incidence of formation of these crystals (MARKWELL et al, 1998), and supplements are recommended to maintain urine at a pH between 6.2 and 6.4 for the prevention of these uroliths and between pH 5.9 and 6.1 for dissolution (ALLEN & KRUGER, 2000). The DL-methionine (DLM) can be used to correct the dietary amino acid balance and as a urinary acidifier (FUNABA et al, 2000). No studies with cats were reported with this molecule It would have higher acidifying capacity compared to methionine. As in pigs, the pH of the urine could be acidified by the inclusion of calcium sulfate (CaSO4) in different doses, being a higher dose responsible for greater acidification (CANH et al 1998)

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