The Food and Drug Administration (FDA) released an alert in July 2018 about high grain food diets being the common denominator in a series of canine dilated cardiomyopathy (DCM) deaths in dogs.
DCM is a disease that affects the heart resulting in an enlarged heart that causes a decreased ability to pump blood. This can cause heart valves to leak creating a build-up of fluid in the chest known as congestive heart failure. DCM is caused by Taurine deficiency. Dogs can metabolise Taurine by synthesising amino acids methionine and cysteine. Straight amino acid Taurine is available in lamb and beef liver. Cats need a direct source of Taurine as they can't synthesise their own like dogs can.
DCM is considered to be more prevalent in dogs that have been on a low meat diet, pet food where there is a lot of grain, cereals and vegetables and low in meat.
Certain breeds, especially many larger dogs are prone to DCM. However, the reported cases also occurred in breeds that are not considered to be genetically predisposed to this disorder.
Moving to a grain free and raw meat diet is likely to help avoid DCM in pets. Many grain free foods now contain a significantly high level of plant protein versus animal protein. Plant protein is fine as a complimentary protein, but dogs require a specific level of animal protein in order to produce all the vital amino acids they need. High levels of Taurine are found naturally in animal-based proteins but it is typically low in plant-based protein sources. While plant protein does provide small amounts of Methionine, it’s not at the levels necessary to be useful as a precursor for Taurine.
In summary, it does appear there is a link between diet and DCM and Taurine levels in pet food. It is almost certainly a combination of factors that can lead to DCM, namely low levels of animal protein, high levels of dietary fibre and a genetic disposition to DCM. To be safe, always look for a high meat based diet – with at least 65% protein from meat. Freeze Dry pet food is also important as it means the nutrients are more bio-available, keeping the food in a raw state.