Exotic-ingredient and grain-free dog food recently became very popular among dog owners, however, they might be linked to serious dog heart disease, canine dilated cardiomyopathy.
The FDA has been studying the long-term effects of grain-free dog foods and their potential link to the dilated cardiomyopathy in dogs. This article summarizes the basics of the topic and the key points of this study every responsible dog owner should know before making any hasty decisions about their dog's diet.
What is canine dilated cardiomyopathy?
Canine dilated cardiomyopathy is a disease in the dog’s heart muscle and results in a weakened and enlarged heart. As the heart becomes larger it’s harder for it to pump the blood through the vascular system.
The cause of the disease is still debated, although mainly nutritional, infectious, and genetic predisposition seems to be responsible for its development.
The most common signs are lethargy, weakness, weight loss due to less oxygen in the blood or coughing, difficult breathing, increased respiratory rate due to congestion of blood in the lungs.
How Can Diet Cause the Heart Disease?
Canine dilated cardiomyopathy used to be the most common heart disease in cats, however in the late 1980s research found that this disease can be associated with taurine deficiency and it can be reversed by supplying additional taurine. After this research, the minimum required level of taurine was increased in cat food and the disease mostly disappeared in cats.
In the early 2000s, studies found that certain dog breeds are more likely to suffer from taurine deficiency and heart disease, but it can be reversed by supplying more taurine in their diet. The taurine deficiency and the associated heart disease in dogs disappeared.
Until very recently veterinarians started to report an unexpectedly high number of heart disease cases in dogs, even in breeds that were not known to be prone to this condition. The dogs involved in these cases were mostly on exotic ingredient grain-free diets, containing kangaroo, duck, salmon, venison, lentils and chickpeas, tapioca, barley.
Not all reported dogs had taurine deficiency, but by supplying them with additional taurine their condition improved. However, as these diets became very popular recently, and even if most of the dogs involved in the cases were eating exotic ingredient and grain-free diets, many other dogs eating the same diets didn't show any symptoms of the disease.
Taurine is not considered an essential amino acid for dogs, because they can synthesize it from cysteine and methionine. Nearly all grain-free products contain these amino acids above the required level, however, the delicate balance of these amino acids is not fully understood.
What are the key findings of the study?
As it was found in earlier studies, the breed of the dog is a very significant factor in the development of the disease. The research shows that large and giant breeds are the most prone to the disease, Golden Retriever being the top breed prone to this disease:
When examining brand names some brands were in the reports more often than the others, however, no product had to be recalled so far as there was no definitive collection found. Arcana, Zignature, and Taste of the Wild brands were the top 3 brands in the reports:
Dog food ingredients showed a stronger link to the disease. Many reported products were labeled as "grain-free" however many of them were not, but still contained legumes, such as peas and lentils:
As the sample size is very small FDA needs to investigate further and gather more data to be able to reliably identify if there’s a link between heart disease and a specific diet.
FDA is inviting dog owners and veterinarians to collaborate and submit any information that might help them in their investigation. A detailed guide to submitting information can be found on "How to Report a Pet Food Complaint".
If your dog is showing symptoms of heart disease; including less energy, cough, difficulty breathing you should urgently contact your veterinarian. Try to keep a good record of your dog’s food history, even including treats. Other pets in the same household and on the same diet should also be studied even if they’re not showing any symptoms.
FDA encourages veterinarians to document and report cases of heart disease in dogs with suspected links to grain-free diet by using their online Safety Reporting Portal.
Pet food must contain all the required nutrients in the right proportions, as part of the regulation. However, the processing of these ingredients also needs to be considered, along with how different ingredients can affect each other.
The grain-free and exotic ingredient dog food marketing reached customers faster than those foods could be studied. Scientific communities continue to investigate the effects of these diets and ingredients before any regulatory decision can be made.