Review of canine dilated cardiomyopathy in the wake of diet-associated concerns

Abstract

<jats:title>Abstract</jats:title> <jats:p>Dilated cardiomyopathy (DCM) has been in the literature and news because of the recent opinion-based journal articles and public releases by regulatory agencies. DCM is commonly associated with a genetic predisposition in certain dog breeds and can also occur secondary to other diseases and nutritional deficiencies. Recent communications in veterinary journals have discussed a potential relationship between grain-free and/or novel protein diets to DCM, citing a subjective increase in DCM in dog breeds that are not known to have a genetic predisposition for the disease. This literature review describes clinical presentations of DCM, common sequelae, treatment and preventative measures, histopathologic features, and a discussion of the varied etiological origins of the disease. In addition, current literature limitations are addressed, in order to ascertain multiple variables leading to the development of DCM. Future studies are needed to evaluate one variable at a time and to minimize confounding variables and speculation. Furthermore, to prevent sampling bias with the current FDA reports, the veterinary community should be asked to provide information for all cases of DCM in dogs. This should include cases during the same time period, regardless of the practitioner’s proposed etiology, due to no definitive association between diets with specific characteristics, such as, but not limited to, grain-free diets and those containing legumes, novel protein diets, and those produced by small manufacturers to DCM in dogs. In summary, in order to determine if certain ingredients, categories of diets, or manufacturing processes are related to an increased risk of DCM, further studies investigating these variables are necessary.</jats:p>

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

“…Genetic makeup or other modifying factors could also influence disease expression in some dogs and explain why not all dogs eating these diets are affected. Alternatively, it remains possible that this apparent association is confounded by other factors 10 . Although some affected dogs are taurine deficient (especially Golden Retrievers 7 ), thereby strengthening the association with food, the majority of dogs with suspected nDCM have normal blood taurine concentrations 6 .…”

The Effect of Fermentation of High- or Low-Tannin Fava Bean on Glucose Tolerance, Body Weight, Cardiovascular Function, and Blood Parameters in Dogs After 7 Days of Feeding: Comparison With Commercial Diets With Normal vs. High Protein

“…However, while pulse ingredients in grain-free diets have been suggested as Abbreviations: ALP, alkaline phosphatase; ALT, alanine aminotransferase; AUC, area under the curve; CK, creatine kinase; CO, cardiac output; CP, crude protein; DCM, dilated cardiomyopathy; DB, direct bilirubin; DBP, diastolic blood pressure; DWT, left ventricular diastolic wall thickness; EDV, left ventricular end-diastolic volume; EF, ejection fraction; ESV, left ventricular endsystolic volume; FM, fermented; FMD, flow-mediated dilation; G6PD, glucose-6phosphate dehydrogenase; GGP, gamma-glutamyltransferase; GLDH, glutamate dehydrogenase; HP, high protein; HR, heart rate; HT, high-tannin fava bean variety; IB, indirect bilirubin; LT, low-tannin fava bean variety; LVID d , left ventricular end-diastolic diameter; LVID s , left ventricular end-systolic diameter; MV, maximum velocity; NP, normal protein; RBC, red blood cell; SBP, systolic blood pressure; SV, stroke volume; SWT, left ventricular systolic wall thickness; TB, total bilirubin; UF, unfermented; VTI, velocity time integral; WBC, white blood cell. causally linked to DCM, the actual link between them has not been definitively demonstrated to date (13)(14)(15). Despite an acknowledgment by the FDA in November 2020 that the link between DCM and diet in dogs is multi-factorial and not due solely to pulses, this issue remains unresolved, leaving veterinarians, and pet owners wary of pulse-containing dog foods.…”

A comparative analysis of two unrelated outbreaks in Latvia and Australia of acquired idiopathic megaesophagus in dogs fed two brands of commercial dry dog foods: 398 cases (2014–2018)

“…Despite extensive investigations, several other food-associated illnesses in people and animals remain unresolved; these include the role of diet in Alzheimer's disease, 11 Fanconi-like syndrome in dogs fed jerky treats, 12 neurologic disease in cats fed irradiated dry cat food, 13 and dilated cardiomyopathy in dogs fed grain-free dog foods. 14,15 Therefore, a cause of diet-associated AIME may not be identified without greater awareness and early detection of disease as well as a thorough epidemiological investigation and sample collection of dietary raw ingredients and tissues from affected dogs.…”