Taurine status in normal dogs fed a commercial diet associated with taurine deficiency and dilated cardiomyopathy

Abstract

Taurine (Tau) deficiencies have been associated with the feeding of commercial lamb-meal and rice diets to dogs. We hypothesized that the poor digestibility of some lamb-meals may limit sulphur amino acids availability for Tau synthesis and/or increase of Tau degradation in the gut. Growing dogs were fed either a lamb-meal-based (Diet A) or poultry by-product-based (Diet B) commercial diet. Plasma, whole blood and urinary Tau were measured for 22 weeks. Plasma and whole blood Tau concentrations were similar between the groups throughout the study. Urinary excretion of Tau in dogs fed diet A was 3.2 times greater than that from dogs fed Diet B, suggesting greater renal reabsorption and the need for conservation of Tau in the Diet A group. Food restriction affected Tau status as indicted by a positive correlation of food intake and urinary Tau. Dogs fed Diet A were given antibiotics to inhibit bacterial activity in the gut. Increases in breath hydrogen, indicative of increased bacterial activity, correlated negatively with urinary Tau. Urinary Tau increased by 54% when methionine (Met) was supplemented to Diet A, supporting the suggestion of a low bioavailability of sulphur amino acids and/or an increased fecal loss of Tau in dogs consuming Diet A.

Taurine deficiency in Newfoundlands fed commercially available complete and balanced diets

“…Taurine is obligatorily lost in urine and in bile acids that are not recovered by means of enterohepatic circulation. 36,37 In taurine-deficient cats, urinary taurine losses are low because of the low concentration of taurine in plasma filtrate and the upregulation of renal tubular taurine transporters. Extraordinary urinary taurine losses cannot be ruled out as a cause for the present observations, in that as much as the urine taurine-to-creatinine ratio is an indicator of urine taurine loss, 35 this ratio appeared to be too high in some dogs in the present study, given their plasma taurine concentrations.…”

Scientific Opinion on the safety and efficacy of taurine as a feed additive for all animal species

“…Thus, the minimum requirement for taurine in dogs fed normal diets is zero (NRC, 2006). Although beneficial effects of additional taurine on dilated cardiomyopathy have been observed in dogs (Kittleson et al, 1997;Tôrres et al, 2003), particularly large breeds (Backus et al, 2006), no recommendations were suggested. The dose was mostly chosen to normalise plasma taurine.…”

Nutrition and cardiomyopathy: Lessons from spontaneous animal models

“…Studies have not consistently shown an association between dietary and circulating taurine concentrations [37]. However, taurine deficiency has been associated with lamb meal and rice based diets and high fiber diets [37][38][39][40][41]. Thus, dietary taurine availability or digestibility may play a role [42].…”