Summary Journal of Animal Science Article, Volume 98, Issue 6, June 2020
In 2018 a blog from a veterinary nutritionist sparked a controversy between ‘BEG’ diets and heart disease in dogs. For the past two years, despite an FDA investigation, scarce and vague scientific data has created major issues for pet owners and the pet industry. For clarity, ‘BEG’ diets are known as Boutique, Exotic protein or Grain Free.
A recent article published in the Journal of Animal Science titled, “Review of canine dilated cardiomyopathy in the wake of diet-associated concerns” that appeared to be a saving grace for many advocates of ‘BEG’ diets. This paper investigated a potential association between grain-free pet food and dilated cardiomyopathy (DCM) in dogs. The authors state, “based on this review of the current literature, there is no definitive relationship between these implicated diet characteristics and DCM.” Despite this statement, realize the purpose of this paper was to identify numerous knowledge gaps surrounding DCM and nutrition, rather than to draw conclusions. While no link between ‘BEG’ (boutique, exotic, grain-free) was found, this does not mean that nutrition and other considerations are not at play.
Background of DCM & Diagnostics:
- Approximately 75% of all heart disease in dogs is chronic degenerative valve disease, with second most common being DCM.
- Genetics play a significant role in purebred and mix breed dogs. In addition, various genes are implicated. Certain breeds have a greater genetic predisposition than others.
- Studies investigating the incidence rate of DCM date back to 1988 until recently. Consistently, the incidence appears to remain between 0.5-1.3% of the canine population. This is inclusive of available FDA data.
- Diagnosis can be limited by accessibility and affordability of various diagnostic tools. Because of this, other types of heart disease could be misdiagnosed as DCM based on similar presentation.
Multiple Causations & Secondary Factors of DCM:
- Biopsy of heart tissue shows numerous underlying causes of DCM – including but not limited to infection, inflammation, endocrine disease, heart arrhythmia, toxins and various nutritional deficiencies.
- Nutritional considerations include fiber content, potassium, choline, methionine, cysteine, taurine, carnitine, thiamine, copper, Vitamin E and selenium. It’s important to note that a deficiency of one or more of these nutrients in direct relation to DCM is an oversimplification and fundamentally incorrect to assume. As discussed below, nutrients have varying and complex roles when it comes to metabolism.
- Other considerations for consideration include cyanide exposure from food (cassava, tapioca), goitrogenic foods (suppress function of thyroid gland), and heavy metals.
FDA Report Considerations:
- Boutique pet food manufacturers and exotic protein sources are likely not associated with DCM per current available data and publications.
- Grain-free foods are also likely not associated with canine DCM, and current data shows any nutritional relationship is likely far more complex than has been portrayed.
- More research is needed to determine risk factors for DCM including, but not limited to, infection, inflammation, endocrine disease, arrythmias, toxins and various nutritional deficiencies.
- The FDA data pool was polluted. Meaning that it was a biased data set with subgroups (like golden retrievers, and dogs eating grain-free food being overrepresented) leading to biased conclusions.