title: Low plasma taurine concentration in Newfoundland dogs is associated with low plasma methionine and cyst(e)ine concentrations and low taurine synthesis.
abstract: Although taurine is not dietarily essential for dogs, taurine deficiency and dilated cardiomyopathy (DCM) are sporadically reported in large-breed dogs. Taurine status and husbandry were examined in 216 privately owned Newfoundlands, a giant dog breed with high incidence of idiopathic DCM (1.3-2.5%). Plasma taurine concentration was positively correlated (P < 0.01) with plasma cyst(e)ine (r = 0.37) and methionine (r = 0.35) concentrations and was similar across age, sex, neutering status, body weight, and body-condition scores. Plasma taurine concentration was low (< or =40 micromol/L) in 8% of dogs. Dogs with low plasma taurine were older, less active, had more medical problems and treatments, and had lower plasma albumin, cyst(e)ine, tryptophan, and alpha-amino-n-butyric acid concentrations than the other dogs (P < 0.05). Of 9 taurine-deficient, clinically evaluated dogs, 3 had DCM that was reversed by taurine supplementation and 1 had retinal degeneration. When given a diet apparently adequate in sulfur amino acids (5.4 g/kg) for 3 wk, 6 Newfoundlands (52.5 +/- 2.3 kg, 3.5-7 y), compared with 6 Beagles (13.2 +/- 2.3 kg, 5.5 y), had lower (P < 0.01) concentrations of plasma taurine (49 +/- 16 vs. 97 +/- 25 micromol/L) and cyst(e)ine and blood glutathione, lower (P < 0.01) de novo taurine synthesis (59 +/- 15 vs. 124 +/- 27 mg x kg(-0.75) x d(-1)), and greater (P < 0.05) fecal bile acid excretion (1.7 +/- 0.2 vs. 1.4 +/- 0.2 micromol/g). Newfoundlands would appear to have a higher dietary sulfur amino acid requirement than Beagles, a model breed used in nutrient requirement determinations.
authors.affiliation: Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, MO 6521, USA. backusr@missouri.edu
authors.forename: Robert C
authors.initials: RC
authors.lastname: Backus
authors.forename: Kwang Suk
authors.initials: KS
authors.lastname: Ko
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: Fascetti
authors.forename: Mark D
authors.initials: MD
authors.lastname: Kittleson
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Macdonald
authors.forename: David J
authors.initials: DJ
authors.lastname: Maggs
authors.forename: John R
authors.initials: JR
authors.lastname: Berg
authors.forename: Quinton R
authors.initials: QR
authors.lastname: Rogers
mesh_terms: D000818:Animals; D001823:Body Composition; D001835:Body Weight; D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000662:veterinary*; D002369:Castration / Q000662:veterinary; D003545:Cysteine / Q000097:blood / Q000172:deficiency*; D019587:Dietary Supplements; D004283:Dog Diseases / Q000097:blood*; D004285:Dogs; D005260:Female; D008297:Male; D008715:Methionine / Q000097:blood / Q000172:deficiency*; D009751:Nutritional Requirements; D013045:Species Specificity; D013654:Taurine / Q000096:biosynthesis* / Q000097:blood / Q000172:deficiency*
chemical_list: D013654:Taurine; D008715:Methionine; D003545:Cysteine