Hope for the Diet-Related Dilated Cardiomyopathy Dilemma
For several years, scientists have been investigating the increase in reported cases of dilated cardiomyopathy (DCM) in dog breeds without a genetic predisposition to this disease. Other factors such as toxin exposure, infectious agents, and/or nutrition could contribute to disease development in these dogs, but diet has received the most attention.
What is Dilated Cardiomyopathy?
Dilated cardiomyopathy, or DCM, is a disease where the heart becomes enlarged and the muscle cannot contract or pump adequately to provide normal blood flow throughout the body. Clinical signs in dogs include increased heart rate, coughing, difficulty breathing, weakness, and fainting. Arrhythmias, congestive heart failure, or sudden death are also possible. Treatment involves the use of medications to support heart function and remove excess fluid from the lungs. Unfortunately, the disease is rarely reversible except in a small number of cases that respond to supplementation with the amino acid taurine.
With funding from the AKC Canine Health Foundation (CHF) Grant 02661: Investigation into Diet-Associated Dilated Cardiomyopathy in Dogs, a team of investigators at several US veterinary colleges screened apparently healthy dogs eating various diet types to better understand the extent of the problem and look for potential causes. They found higher levels of troponin in dogs eating diets that were grain-free or had peas, lentils, and potatoes as main ingredients.1 Troponin is a protein found only inside heart muscle cells. It leaks into the blood stream when heart muscle cells are damaged, making it a good biomarker or indicator of heart damage. Investigators hypothesized that these increased troponin levels indicated low-level heart muscle cell damage in these otherwise healthy dogs.
While the investigation into diet-related DCM continues, CHF awarded a Summer Veterinary Student Educational Grant to Dana Haimovitz, a veterinary student at the University of Florida, to assist Principal Investigator Dr. Darcy Adin with data collection and analysis. Ms. Haimovitz (class of 2023) analyzed data on 20 dogs eating grain-free diets with subclinical heart damage from the original study. Physical exams, blood tests, and echocardiograms were performed on these dogs every three months for one year to see if their subclinical heart damage would improve after a diet change. In fact, troponin levels and left ventricular internal systolic diameter (a measure of heart contraction or function) decreased after one year of eating a diet containing grains. These results were presented during a poster session at the 2021 AKC Canine Health Foundation National Parent Club Canine Health Conference and were recently published in the Journal of Veterinary Internal Medicine.2
Additional study is ongoing to explore exactly how grain-free diets or those with peas, lentils, and potatoes as main ingredients contribute to subclinical heart damage and DCM in dogs. However, these latest findings offer hope. Results show that heart muscle cells can recover, and that subclinical damage appears to be reversible.
CHF and its donors remain committed to studying diet-related DCM and other types of canine heart disease. Learn more about this research at akcchf.org/cardiologyRPA. Working together, we can help all dogs live longer, healthier lives.
Adin, D, Freeman, L, Stepien, R, et al. Effect of type of diet on blood and plasma taurine concentrations, cardiac biomarkers, and echocardiograms in 4 dog breeds. J Vet Intern Med. 2021; 1– 15. https://doi.org/10.1111/jvim.16075
Haimovitz, D., Vereb, M., Freeman, L., Goldberg, R., Lessard, D., Rush, J., & Adin, D. (2022). Effect of diet change in healthy dogs with subclinical cardiac biomarker or echocardiographic abnormalities. J Vet Intern Med. https://doi.org/10.1111/jvim.1641
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