Once again, pet food ingredients are in the news and under the regulatory spotlight, and possibly for all the wrong reasons. The U.S. Food and Drug Administration’s (FDA) announcement last week that it is investigating a potential link between certain types of dog food ingredients and recent cases of canine dilated cardiomyopathy (DCM) has spurred media coverage and caused hurried conversations and ripples of concern within the pet food industry. And rightly so — yet was FDA’s announcement premature, considering so little is yet known?
One pet industry expert believes so. “There is a troubling lack of information behind this announcement — and that could very well result in an unnecessary panic that would have catastrophic impact on the pet food industry,” wrote Mark Kayalgian, publishing director and editor-in-chief of Pet Business magazine. “Taken at face value, this warning is alarming, to say the least. However, when you look more closely, it becomes clear that there is very little hard evidence about what connection the ingredients might have to DCM — if there is any connection at all.”
Amen. And with there being so little information to go on at this point, it seems FDA has fallen into the same trap that many consumers and — let’s face it — some pet food companies do: focusing on individual ingredients rather than on the nutrients being delivered and the overall nutritional balance of the dog foods in question.
It’s not necessarily about grain-free pet foods
To recap, owners and veterinarians have reported cases of DCM in dogs of breeds not usually associated with or genetically predisposed to the condition. The dogs in these cases have been eating diets listing potatoes or multiple legumes such as peas, lentils and pulses, and their protein, starch and fiber derivatives, early in the ingredient list, indicating they are main ingredients in the foods, according to FDA reports. Of course, that type of ingredient panel is one of the hallmarks of popular grain-free pet foods.
I first heard that the FDA announcement was imminent during SuperZoo at the end of June. When I asked several well-regarded and experienced companion animal nutritionists about it, they all had the same response: if diet is a cause or contributor to these cases of DCM (and that’s still a big “if”), it’s likely due to the formulation matrix, not the individual ingredients. In other words, the balance and proportion of the ingredients in relation to each other, how they are processed and — most importantly — whether the diets are delivering essential nutrients to the dogs.
These nutritionists weren’t (and still aren’t) offering this response to necessarily defend grain-free pet foods; rather, they’re pointing out the nutritional reality of formulating today’s complex, premium products.
The problem with high levels of legume seeds in pet foods
Greg Aldrich, Ph.D., president of Pet Food and Ingredient Technology, happened to write about legume seeds in his most recent Ingredients Issues column in early June, weeks before FDA released its warning. (As far as I know, he wasn’t aware of the pending announcement at the time.)
“These legume seeds bring great variety to the pet aisle, have more protein than the cereal grains and possess other phytonutrients considered valuable to overall health,” Aldrich wrote. “However, they carry with them significant quantities of fermentable oligosaccharides. In small amounts these may be beneficial to the animal, but at large concentrations they can become an issue.” He added that limited-ingredient, grain-free diets especially tend to have very large amounts of legume seeds, up to 40 percent of the formula, which can have a significant impact on the level of fermentable fiber in the colon.
“Yes, there may be some benefit, but there can also be some challenges,” Aldrich continued. “Notably, this amount of excess fermentable substrate can tip the balance in the colon, shifting the populations within the colonic environment and altering the osmotic balance and gas production. That is to say, the contents of the bowel become more fluid and the result is soft stools, diarrhea and flatulence. There may also be alterations to nutritional balance by changing things like the enterohepatic recirculation of taurine and reductions in mineral utilization.”
Note the mention of taurine: in four of the recently reported, atypical cases of DCM, the dogs had low blood levels of taurine; low taurine can contribute to development of DCM. On the other hand, with four other cases of atypical DCM, the dogs’ taurine levels were normal.
Lack of dog and cat nutrition research the fundamental issue?
So we’re back to the original point: this investigation is still in very early days, and there truly is no information or data, at least not yet, showing a definite connection between the ingredients indicated and the atypical cases of DCM.
FDA admits as much. “It is still early in the investigation and right now we’re simply notifying the public, practitioners and manufacturers that we are observing a signal that warrants further study,” said Anne Norris, a Center for Veterinary Medicine health communications specialist. “The common thread seems to be legumes and/or potatoes as main ingredients in the food. Currently, it’s a correlative link, not a causative one. We’re hoping that after receiving data from pet owners and veterinarians, we will have more data to further inform our investigation.”
In a recent conversation, Aldrich said that, in addition to high levels of fermentable colonic fibers possibly contributing to taurine depletion, such a heavy reliance on legume seeds in a formulation can throw off the nutritional balance and create the risk of insufficient levels of other essential amino acids like methionine and cystine. There is also the possibility that other dog breeds, or families of breeds, may be predisposed to DCM, in addition to the ones known to be.
And that points to the true, underlying problem: we just don’t know enough about dog and cat nutrition, due to an ongoing lack of published research and data available. This issue continues to hamstring pet food companies and the industry — and, by extension, pet retailers and owners — in the desire we all share to ensure pets are receiving the best nutrition possible, in ways that consumers can afford, understand and feel comfortable feeding. Even the agency responsible for regulating pet food in the U.S. gets caught up in the lack of knowledge and proven scientific information about the ingredients and nutrients comprising pet food, issuing premature warnings in the process.