Effect of type of diet on blood and plasma taurine concentrations, cardiac biomarkers, and echocardiograms in 4 dog breeds

Abstract

Background: Associations of diet with dilated cardiomyopathy are under investigation. Objectives: That cardiac assessment would show abnormalities in healthy dogs eating grain-free (GF) diets or diets with Food and Drug Administration (FDA)-listed ingredients of concern (peas, lentils, or potatoes) as top 10 ingredients (FDA-PLP), but not in dogs eating grain-inclusive (GI) diets or diets without FDA-listed ingredients of concern (PLP) in the top 10 ingredients (NoFDA-PLP). Animals: One hundred eighty-eight healthy Doberman Pinschers, Golden Retrievers, Miniature Schnauzers, and Whippets. Methods: This study was an observational cross-sectional study. Echocardiograms, cardiac biomarkers, and blood and plasma taurine concentrations were compared between dogs eating GF (n = 26) and GI (n = 162) diets, and between FDA-PLP (n = 39) and NoFDA-PLP (n = 149) diets, controlling for age and breed. Demographic characteristics, murmurs, genetic status, and ventricular premature complexes (VPCs) during examination were compared between dogs eating different diet types. Results: No differences in echocardiographic variables, N-terminal pro-B-type natriuretic peptide or whole blood taurine were noted between dogs eating different diet types. Dogs eating GF diets had higher median high-sensitivity cardiac troponin I (hs-cTnI) (GF 0.076 ng/mL [Interquartile range (IQR), 0.028-0.156] vs. GI 0.048 [IQR, 0.0026-0.080]; P < .001) and higher median plasma taurine (GF 125 nmol/mL [IQR, 101-148] vs GI 104 [IQR, 86-123]; P = .02) than dogs eating GI diets. Dogs eating FDA-PLP diets had higher median hs-cTnI (0.059 ng/mL [IQR, 0.028-0.122]) than dogs eating NoFDA-PLP diets (0.048 [IQR, 0.025-0.085]; P = .006). A greater Abbreviations: EF, ejection fraction; FDA, Food and Drug Administration; FDA-PLP, diets with FDA-listed ingredients of concern (peas, lentils, potatoes) in the top 10 ingredients; FS, fractional shortening; GF, grain free; GI, grain inclusive; hs-cTnI, high-sensitivity cardiac troponin I; LA/Ao, left atrial to aortic diameter; LV, left ventricular; LVIDdN, normalized left ventricular internal diameter in diastole; LVIDsN, normalized left ventricular internal diameter in systole; LVVd/m 2 , left ventricular volume in diastole indexed to body surface area; LVVs/m 2 , left ventricular volume in systole indexed to body surface area; nDCM, nutritional dilated cardiomyopathy; NoFDA-PLP, diets without FDA-listed ingredients of concern (peas, lentils, potatoes) in the top 10 ingredients; NT-proBNP, N-terminal pro B-type natiuretic peptide; PLP, peas, lentils, potatoes.

Responses in randomised groups of healthy, adult Labrador retrievers fed grain-free diets with high legume inclusion for 30 days display commonalities with dogs with suspected dilated cardiomyopathy

“…However, this area deserves further investigation as released heme can cause oxidative damage by radical oxygen species, impaired nitric oxide signalling, endothelial dysfunction and systemic vasoconstriction, which may impact heart structure and function [ 27 ]. Feeding grain-free diets and diets containing peas, lentils or potatoes to dogs has recently been linked to increased median cardiac troponin I and plasma taurine, both suggested by Adin et al to originate from damaged cardiomyocytes, while no changes in whole-blood taurine or NTproBNP were observed [ 18 ].…”

“…Historically, DCM was most prevalent in genetically predisposed large and giant breed dogs [ 3 – 5 ] or as a result of taurine deficiency [ 6 , 7 ], which in dogs has been limited to certain breeds [ 7 – 15 ] suggesting genetic factors influencing taurine biosynthesis/metabolism. Although taurine deficiency was considered as a cause of the recent DCM cases, factors indicate that this may not always be the case: 1) reported diet, whole blood and plasma concentrations of taurine have in most cases been within recommended ranges [ 1 , 2 , 16 , 17 ]; and 2) affected dogs are represented across a wider range of breeds/sizes and ages [ 1 , 2 , 18 ]. Further support for a dietary aetiology is provided by improvement of DCM when dogs are transitioned onto conventional, grain-inclusive diets, either with or without additional taurine supplementation [ 1 , 2 , 16 , 19 , 20 ].…”

Prospective study of dilated cardiomyopathy in dogs eating nontraditional or traditional diets and in dogs with subclinical cardiac abnormalities

“…Three studies in apparently healthy dogs now have provided some evidence that NTDs are associated with negative cardiac effects (larger left ventricular diameter, lower left ventricular systolic function, higher hs‐cTnI concentrations, more arrhythmias) even in apparently healthy dogs. 43 , 44 , 45…”

“…Definitions for NTDs have varied among studies and have been refined over time as additional data on this disease have accumulated. 14 , 15 , 16 , 17 , 18 , 43 , 44 , 45 The definition of NTDs used in our study focused on the presence or absence of ingredients, rather than subjective criteria. This definition still might not be optimal because, until the exact cause is known, it is impossible to specifically target ingredients or certain compounds that are lacking or in excess in the food.…”

“…18 healthy dogs now have provided some evidence that NTDs are associated with negative cardiac effects (larger left ventricular diameter, lower left ventricular systolic function, higher hs-cTnI concentrations, more arrhythmias) even in apparently healthy dogs. [43][44][45] Our study had some additional limitations. Although most dogs in both DCM diet groups had CHF, others had no clinical signs and, even in dogs with CHF, severity varied.…”