By Dr. Ryan Baumwart & Dr. O. Lynne Nelson
Many dog owners have switched their pets to grain-free, exotic-ingredient, vegetarian, vegan, or home-prepared diets over the past decade. The trend toward these “boutique diets,” however, has coincided with an increase in reports of dogs with dilated cardiomyopathy, the most common cause of heart failure in certain large breed dogs.
What is dilated cardiomyopathy?
Dilated cardiomyopathy is a disease of the heart muscle that results in weakened contractions and poor pumping ability. As the disease progresses, the heart chambers become enlarged, valves may leak, and signs of congestive heart failure develop. While the disease is not always severe enough to cause symptoms, in other cases it can be life-threatening or even fatal due to an irregular heartbeat and congestive heart failure. Read more about dilated cardiomyopathy.
Historically, dilated cardiomyopathy was primarily seen in breeds known to have a genetic predisposition to the disease, but in recent years the U.S. Food and Drug Administration reported an increase in the number of cases in other breeds. In many of the cases, the affected animals were being fed “boutique diets.” The FDA alerted the public to the issue in 2018, and since then veterinary researchers have been investing the role of diet in the increased reports.
What we know
There has historically been evidence of diet-responsive dilated cardiomyopathy in some breeds (golden retrievers, cocker spaniels, but the incidence in these breeds has appeared to increase when eating grain-free, vegetarian/vegan, or exotic-ingredient foods. In other cases, the breeds of dogs developing dilated cardiomyopathy appear unusual, meaning the dog does not have a breed history of an inherited type of the disease, or the dog may be young.
Recent studies have identified significant differences in more than 30 vitamins and amino acid compounds in boutique diets compared to standard diets, suggesting that dogs’ bodies could process boutique diets differently. The reason that some dogs are affected with DCM verses others is still under investigation.
Taurine deficiency may be a factor in some breeds (those listed above), but it is unclear whether it is a cause or merely an association with yet unknown other dietary components.
Dogs with dilated cardiomyopathy that have been eating the diets described above may reverse the condition if it is caught early or if they respond favorably to a change in diet.
What we recommend
If your dog does not have a medical condition requiring alterations in specific dietary ingredients, we recommend feeding a diet made by a well-established manufacturer that contains standard ingredients and has a record of long-term nutritional research. Extended feeding trials appear to be a key factor in determining if a diet is safe to feed long term.
If your dog has been diagnosed with dilated cardiomyopathy and is eating a boutique-type diet, we recommend changing the diet and measuring whole blood and plasma taurine levels if the breed is known to be taurine sensitive.
- If taurine levels are low or on the low end of the normal range, dietary supplementation of taurine should be added.
- Follow-up echocardiography should be performed in 3, 6, and 12 months to assess for improvement in heart function after diet change.
- Screening echocardiography for dilated cardiomyopathy should be performed in all dogs of the same household eating the non-standard diet.
If your dog has a medical condition that requires a non-standard diet, we suggest a diet made by a well-established manufacturer that has undergone extensive Association of American Feed Control Officials (AAFCO) feeding trials. Your veterinarian can help you choose an appropriate diet for your dog’s medical condition.
WSU veterinary cardiologists Ryan Baumwart, DVM, ACVIM-CA and O. Lynne Nelson, DVM, ACVIM-CA, IM are board-certified in companion animal cardiology.
This information is not meant to be a substitute for veterinary care. Always follow the instructions provided by your veterinarian. Washington State University assumes no liability for injury to you or your pet incurred by following these descriptions or procedures.