Mutt’s Happening: The DCM Scare

A year ago, the U.S. Food and Drug Administration publicly raised concern to the public about the increasing caseload of Dilated Cardiomyopathy (DCM) in dogs. In July of 2018, the FDA’s press release stated a “potential connection between diet and cases of canine heart disease” in reference to grain-free diets from high quality “boutique” food brands. In July of 2019, the FDA released 16 pet food brands and the number of DCM cases they suspect are associated with each brand, raising concerns from pet owners who feed their dogs that food on how to proceed. Although the FDA has stated that “it is not yet known how these ingredients are linked to cases of DCM” and that “the underlying cause of DCM is not truly known”, many confused customers are unsure about the information that has been coming to the public’s attention. Here are some facts and tips about how to make good choices for your dog.

What is Dilated Cardiomyopathy?

Dilated Cardiomypathy (DCM) is the degeneration of the heart muscle, leading to weakened contractions and pumping ability. The heart muscle becomes enlarged from the pressure of the blood, which causes the thin muscle to spread, further straining the heart. The basis for this disease was thought to be genetic, as certain breeds were more predisposed than others. Most of the predisposed breeds, including Great Danes, Portuguese Water Dogs, Boxers, and Dobermans, are relatively bigger dogs, but the occurrence of the disease in smaller dogs like Shih Tzus suggests that there may be multiple factors.

What is taurine?

Taurine is an amino acid that is synthesized from two other amino acids: cysteine and methionine. These amino acids can be found in animal based proteins such as beef, chicken, turkey and fish, but not grain. Dogs, unlike cats, are able to produce their own taurine from cysteine and methionine, but they need enough of that protein for synthesis to occur. The dog foods that have come under fire have used legumes (chickpeas, peas, beans) as a substitute for grain. The lack of grain in diets does not cause DCM because grain is not a source of cysteine or methionine (therefore not a source of taurine). The studies have been largely inconclusive because some dogs with normal taurine levels have DCM, whereas some dogs have low taurine levels and no DCM. However, there is a theory that the legumes used as a grain substitute might interfere with the synthesis of taurine. Foods with healthy levels of taurine inclue meat, eggs and seafood (taurine is not found in any plant based proteins).

Important Things to Remember

  • A high number of grain free diets have been involved, but DCM is caused by many variables that cannot be explicitly connected to the diet
  • The legumes in food are accepted as safe and healthy because they do not form the majority of the diet
  • The sample size of the dogs involved in the study is a very small portion of the dogs eating the food, and there are many other factors (breed, pre-existing conditions, exercise) that are unable to be measured
  • The three most common proteins being fed across all cases are chicken, lamb, and salmon, which are not classified as “exotic proteins” often incorrectly associated with fancy, grain-free diets
  • Grain-free food had similar levels of protein, fat, fiber, starch, cysteine, methionine and taurine as the grain-containing food, according to the FDA’s July 2018 study

What Can Pet Owners Do?

As a dog owner, the best thing you can do is make informed decisions about the health of your dog, because each dog is an individual. Although the FDA has published data, they, along with other renowned scientists and veterinarians, have accepted that the cause of DCM is still inconclusive and the results are incomplete.

  • Vary your dog’s diet. There is such thing as too much of something, no matter how nutritious it is. Rotating and varying food is an important way to combat excesses and keep your dog healthy. This avoids gastrointestinal sensitivity and keeps your dog food fresh (so your dog can be eating new food, and so you can avoid overbuying). It is important to understand that your pet might react better to some ingredients than others, so there may be a process to understanding the right diet rotation.
  • Choose good ingredients. It is impossible to draw conclusions about which ingredients are healthy and which aren’t, but many veterinary experts have agreed that many foods are good in moderation. Food should have a lot of animal-based protein to supply your pet with the proper sulfur-containing amino acids (cysteine and methionine) so they can synthesize their own taurine to maintain a healthy heart. Making sure that these proteins constitute the majority of the food is important, because filler ingredients that often are not fresh or healthy can be detrimental.

Finally, some symptoms of DCM in dogs are an elevated heart rate, coughing, fainting, lethargy, loss of appetite, and pale gums. If you think your dog is suffering, don’t hesitate to take them to the vet. Because the information on DCM and its causes are still not known fully, don’t make any rash or large changes to your pet’s diet if they are thriving already!