Dilated Cardiomyopathy (DCM) is a heart condition where the heart muscle becomes flabby and stretched out and unable to properly contract. This leads to heart failure because the heart is not able to move blood through the body and the blood backs up. If you think of the heart as a pump and the vessels as pipes, basically the pump loses power and is no longer able to push blood through the pipes. There are some breeds that we know are predisposed to this. Boxers, Dobermans, Great Danes and Cocker Spaniels are the most common breeds to get this disease in the past. Within the last few years other breeds have started being diagnosed with this disease at an unusually high rate. Researchers have been trying to figure out why so many dogs were being diagnosed with a disease that has not affected their breed significantly in the past.
This is where the story gets interesting (and scary). Researchers started noting a correlation between dogs getting DCM and dogs eating grain free food. In science, extreme caution is used to make sure there is actual causation (something causes something else to happen), not just correlation (a connection between 2 things). What this means is, we don't want to blame something that is happening simply because 2 things are happening at the same time. We want to make sure that a + b= c. If you have a and b, do you consistently get c? Or does a and b just happen to happen in the same population and a = c or b = c and a and b have nothing to do with each other. I realize this can be confusing but suffice it to know that researchers have looked in depth in this and have concluded that gran free diets can cause DCM in dogs with no genetic predisposition.
It is still unclear why grain free diets cause DCM. What has been found is legumes (peas, lentils, potatoes) seem to block the absorption of taurine. Taurine is an amino acid that is essential to cardiac health. This means that even with additional taurine supplementation, some dogs are getting DCM when being kept on grain free foods. DCM has been reversed in some cases when the dog is taken off the grain free food, but not in all cases. Meaning if the dog is diagnosed with food related DCM, changing the diet may or may not help (but is definitely the first step).
The FDA has been collecting data about new DCM cases and tracking what foods these dogs are eating. They have compiled it into the article I link to below. There are some brands that are massively over represented with cases of DCM. The dog food industry is for the most part unregulated. This means you can start a dog food company and make any number of claims and not test your food and still be allowed to sell it. Some companies have veterinary nutritionist on their staff that make sure the food is balanced. Some companies actually test their food on real animals to make sure it is a good food and the dogs will not get sick from it and do well on it. A food can look balanced on paper but when fed to real animals, it does not perform as expected. The companies that have had no cases of DCM are companies that both have nutritionist on staff and test the foods in feeding trials. If a food has been tested using AAFCO feeding trial, it will be labeled as such. Royal Canin, Purina, Science Diet, Iams/ Eukanuba have not had any confirmed cases of dogs getting DCM while being fed their food.
If you are feeding a brand that is listed in the article as being linked to DCM, we encourage you to switch their food. If you have questions about your pets diet, we would be happy to discuss it with you. There are still a lot of unknowns at this point. This is an evolving topic that we are following very closely and will keep you updated as more is discovered.