DCM . correlation


Within this thread, I posted full citation to one published peer reviewed article discrediting the methodology and conclusions of a paper that identified a mere correlation between DCM and grain-free diets (that is a gross over simplification of how they approached the matter – they actually looked at a variety of chemical compounds found in a variety of diets, some identified with grain substitutes like peas and potatoes) and another article that is in the final stages of peer-reviewed publication showing that despite a 500% increase in the feeding of grain free diets, there has been no corresponding increase in the incidence of diagnosed DCM.

THAT seems fairly persuasive that despite the identification of a correlation, they have been unable to find a causal connection between grain-free diets and DCM.

That happens a lot; correlation is not a synonym for causation.

For example, there is also an identified correlation between ice cream sales and murder rates – but, you (hopefully) don’t think ice cream causes murder, right?

If you look more deeply at ice cream and murder, you find there is a correlation between the day’s temperature and murder rates and the day’s temperature and ice cream sales. Thus, there are two separate causal effects brought on by a heat wave. As a result – two unrelated activities correlate without any actual causation.

There are good and bad reasons to change your dog’s diet and to go grain free, but DCM fears aren’t among the good ones, unless you’re also scared you’ll become a murderer if you buy ice cream when it’s warm outside.

I made the original suggestion that OP consider a dietary change because my lab/rott had skin issues that three types of antibiotics and two fungicides (not to mention several inconclusive path reports from submitted skin samples) could not sort out. After going grain free, his black coat gleamed in the dark, his hot spots disappeared, and he had no more ear infections. His odor changed dramatically as well, though I hadn’t identified it as a problem before the diet change – I just figured that was his dog smell. The one time I later bought a bag of IAMS (made with both corn and wheat) from the grocery store because I forgot to pick up his usual brand, all his skin issues were back before the bag was half gone.

So, my personal observations with a large breed dog noted that going grain free made an enormous difference in his quality of life, and the observed improvements disappeared when the grain was reintroduced.

I do not know whether OP would have the same experience; one anecdote does not provide enough data for a conclusion, but the plural of anecdote is data, and some things you cannot know until you try.

I submit that sort of potentially positive gain in the face of no identified gamble makes it a perfectly reasonable route to pursue

In the peer-review pipeline awaiting final publication:

“We hypothesized that DCM incidence among breeds could be estimated by retrospective polling of veterinary cardiologists. Further, if a correlation existed between grain-free diets and DCM, an increase in DCM would be on trend with increased grain-free pet food sales.”

“Fourteen hospitals participated and reported 67,243 unique canine patients. Nationally, data did not support a significant change in percent DCM over time (p=0.85). The overall average incidence rate of DCM during the study period was 3.83% (range 2.41-5.65%), while grain-free diet sales increased 500% from 2011-2019. No correlation between overall DCM incidence and grain free diet sales was discovered. A significant upward trend in mixed breeds diagnosed with DCM, with no significant trend in other breeds was appreciated. An upward trend in age at DCM diagnosis was identified, correlating with trends from overall hospital populations.”

“These data do not support overall increased DCM incidence, or a correlation with grain-free pet food sales. Additional data are necessary to understand whether regional factors contribute to increased DCM within smaller cohorts.”

Incidence of canine dilated cardiomyopathy, breed and age distributions, and grain-free diet sales in the United States from 2000-2019: A retrospective surve

“‘While determining the cause of recently reported cases of cardiac disease is of the utmost importance, based on this review of the current literature, there is no definitive relationship (between) these implicated diet characteristics and DCM,’ according to the study, which involved an exhaustive examination of nearly 150 previous studies.

The new study pointed to potential sampling bias and other confounding factors for debunking the claim – saying the scrutiny comes ‘without merit because there is no definitive evidence in the literature.’


By tranthe

We never say no to any dog – mixed breeds, banned breeds, disabled dogs and seniors. We try to rescue them all. Unfortunately, we cannot do that without the public’s continued support.

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