Unravelling Dilated Cardiomyopathy

Hi everyone and welcome to Val Talk’s Pets.  Well this edition is one that has caused controversy, mayhem with dog’s diets, and basically left many pet owners very confused as to what to feed their dogs.  I am talking about DCM, Dilated Cardiomyopathy.  If you haven’t heard of this yet, well maybe that means the panic and knee jerk reactions have settled down, or it just hasn’t reached your ears as of yet.  So, I’m going to try and wade through this miasma of misinformation, look at some peer reviewed papers and see if I can’t help pet parents navigate through this rather confusing health issue.

So what is DCM?  DCM as I stated is Dilated Cardiomyopathy. It is a type of heart disease predominately in large and giant breed dogs.  According to Upstate Veterinary Specialities, there is a “progressive heart muscle dysfunction, chamber dilation and eventual congestive heart failure or death of affected patients. “  As also stated, “the exact cause of the condition is unknown but genetic factors are presumed to play a role”.  Basically, the heart muscle enlarges and it becomes harder for the heart to pump.  According to VCA Canada.com, Dr. Ryan Llera and Dr. Ernest Ward contributed to an article that states that, “DCM is the most common cause of heart failure in certain large breeds of dogs.  These include, Boxers, Dobermans, Great Danes, Irish Wolfhounds and Saint Bernard’s. Occasionally German Shepherds and some medium-sized breeds such as Cocker Spaniels, English Springer Spaniels and Portuguese Water Dogs are also affected.  Small breeds rarely develop DCM.  It is most often diagnosed in males rather than females.”  

In early 2019, the FDA, Food and Drug Administration in the U.S. released a statement that said that there was a possible link between DCM and dogs eating diets containing peas, lentils, potatoes and other legume seeds as a main ingredient.  Now, if you have ever shopped for grain free food for your pet, you will have noticed that often potato is in the ingredient list and peas and you may also see chick peas or garbanzo beans as well, which would be considered a legume. But, note whether these are main ingredients.  So, what was being investigated was the connection of dog foods formulated with potatoes and pulse ingredients.  Pulse ingredients are powders made from fractions of high-quality lentils, peas, chickpeas and faba beans.  And from here, the connection was made to an amino acid called taurine.   Taurine is a sulfur-containing amino acid important in the metabolism of fats.  It is considered the most abundant amino acid in the heart, retina, skeletal muscle, brain and immune cells.   Its function with regards to the heart is what we are interested with regards to DCM.  Taurine is derived from most animal products and by-products.  So, meat, fish and dairy.  Taurine as stated is important in metabolizing fats, and it does this through activating the bile acids in the liver, enabling them to break down fats.  Cats do not produce taurine so they have to get it from their diets which as carnivores they would get from eating animal protein.  Dogs on the other hand can make taurine using two other amino acids, methionine and cysteine.  Quoting from a paper released by Dr. Jennifer Adolphe, Michele Dixon and Natalie Asaro, animal nutritionists, “Taurine is not considered necessary in dog’s diets if enough methionine and cysteine are present”.  Now animal based foods are actually good sources of these two amino acids.  

So at this point are you confused?  I hear constantly from pet parents that their vet told them to never feed grain free food because it causes DCM.  Hmmm?  Why is that?  Well the connection is made to taurine deficiency and connects in particular Golden Retrievers fed a commercial diet.  Okay, let’s put a pin in the word “commercial” and circle back to that.  Golden Retrievers were high on the list of taurine deficiency as well as Newfoundland dogs and Springer Spaniels, fed commercial diets. A paper produced by PubMed.gov reveals in the Abstract, “that 23 out of 24 dogs diagnosed with taurine deficiency and dilated cardiomyopathy were fed diets that were either grain-free, legume-rich, or a combination of these factors.  None of these diets were feeding trial tested using Association of American Feed Control Officials or AAFCO procedures.  Twenty-three of 24 dogs had significant improvement in their echocardiographic parameters and normalization of taurine concentrations following diet change and taurine supplementation.  Nine of 11 dogs diagnosed with congestive heart failure had resolution of their congestion at follow-up with five no longer requiring diuretic therapy and four tolerating diuretic dose reduction by 50%”.  Here is the conclusion of the paper. “Certain diets and diet characteristics were associated with the development of taurine deficiency.  Taurine deficiency and dilated cardiomyopathy in golden retrievers is likely multifactorial, including a combination of dietary, metabolic, and genetic factors.”  What I hear in this statement is that proper testing has not been done and we are looking at more than one culprit that may contribute to DCM and specifically in certain breeds.  As Dr. Adolphe et al, points out, “Millions of healthy dogs around the world eat grain-free diets their entire lives; this is the first time that grain-free diets have been implicated as a potential cause of heart disease.  Complicating the matter further is that genetics may also play a role in the development of DCM.”   

Let’s follow Dr. Adolphe a bit further and look at protein.  Now as stated, dogs can produce taurine if there is enough methionine and cysteine in the animal protein of their food.  Now, if you remember in my last episode on fillers, one of the issues was the quality of the overall product and the quality of the individual ingredients.  Well, this where this quality issue comes into play again.  The Adlophe paper states, “lower quality animal-based proteins, (i.e. those that provide low levels of one or more essential amino acids) may not provide adequate methionine and cysteine for dogs to produce enough taurine.  Knowing this, it’s crucial to consider ingredients protein quality when formulating foods for both dogs and cats.  Pet foods are also often supplemented with single amino acids, particularly methionine, lysine, and taurine to ensure sufficient amounts.”   

Now we can circle back to the idea of “commercial” pet foods.  If we look at the commercial level of pet foods, meaning those in grocery or big box again, what is at issue is the quality of the ingredients despite sometimes looking the same as pet speciality.  In this case, the quality is extremely important to make sure that enough methionine and cysteine is present and that the product also has supplemented with added taurine.  I can tell you that taurine is present in just about every food in store, and at levels much higher than the base requirement. 

So far what we have deciphered is that lower quality food can definitely be at issue for contributing to DCM.  When choosing food for your pet, quality is optimum and a good animal based protein list with added taurine is also optimum as a paper published in 2019 by Oxford University Press on behalf of the American Animal Science with contributions from many Universities and authors, it states, that “low dietary taurine intake and/or reduced synthesis of taurine from methionine and cysteine can deplete calcium pools in the cardiac cells and impede proper contraction of the cardiac muscle tissue, resulting in DCM in dogs.”  Again, an issue with quality but this also launches into what else could be a contributing factor in DCM and food.  

One of the other contributing factors mentioned is the higher level of potatoes and pulse ingredients used in grain free formulas.  The issue surrounding the use of peas and legumes was mentioned.  I was on a webinar with a holistic veterinarian out of Florida and one thing she mentioned was that there is some research being done with regards to a possibility that the peas and legumes may impede the absorption of the taurine.  So here is where I think I can break this into something more understandable.  Taurine comes from meat and meat by-products.  Methionine and cysteine come from grains.  These two amino acid precursors help synthesize the taurine.  As stated by the American Animal Science contribution, reduced synthesis of taurine can deplete calcium pools in the cardiac cells and impede proper contraction of the cardiac muscle tissue, resulting in DCM in dogs.  If the food is grain free then these two precursors may not be present and most likely have legumes in place of the grains. Remember though, high quality foods will add methionine and taurine.   At present there is no data that links the legumes to impeding the assimilation of taurine or to DCM but what really would be at issue is the lack of methionine and cysteine.  A paper from August 2021 from theguardian.com, explains, that “upon detailed analysis through a process called foodomics, researchers found that the ingredient most strongly linked to suspect compounds was peas.  However, the FDA is not considering a ban on peas in dog foods yet.  According to the agency, because, “legumes and pulses have been used in pet foods for many years, [there is] no evidence to indicate they are inherently dangerous.  Rather, the problem may be one of quantity as the FDA’s Center for Veterinary Medicine, “indicates that pulse ingredients are used in many grain free diets in greater proportion than in most grain-containing formulas.”  What I find is causing a lot of confusion is the statements that grain free food lacks taurine and therefore causes DCM.  Well that’s impossible because taurine comes from meat.  It is the two amino acids methionine and cysteine from grains that are the synthesizers for taurine or what is needed to absorb the taurine.  So, taurine and meat are not at issue.  The FDA updated its research this past August, looking into what is called non-hereditary forms of DCM and according to hemopet.org “forms of DCM occur in dogs as a complex medical condition that may be affected by the interplay of multiple factors such as genetics, underlying medical conditions and diet.  Aspects of diet that may interact with genetics and underlying medical conditions may include nutritional makeup of the ingredients and how dogs digest them, ingredient sourcing, processing, formulation and/or feeding practices.”  Well doesn’t that just make things as clear as mud. And to make things even more grey, the FDA has received reports of non-hereditary DCM associated with both grain free and grain-containing diets. Well that’s because many grain-containing diets also use pulse ingredients, if indeed pulse ingredients are contributing.  And in the investigation, the FDA did not find one vegetarian or vegan dog food implicated when these are entirely plant based diets containing some of the highest levels of peas, lentils and potatoes.  So, as you can see this is a really difficult topic and really the answer to how dogs present with DCM is that there is no definitive answer.  

Let’s see though if I can summarize.

DCM, dilated cardiomyopathy can affect certain breeds particularly Golden Retrievers and other large breed dogs. These would be considered hereditary DCM.

Grain free foods are targeted because it was thought that the lack of grains meant a lower level of two amino acids methionine and cysteine found in grains would reduce the absorption of taurine. But, remember in a good quality food the methionine and the taurine is added in a supplementation. 

Grain free foods often have a higher level of potatoes, peas and legumes or pulse ingredients.  At this point there is no evidence to suggest that legumes is impeding the absorption of taurine but peas may be at issue but again, at this point there is no data to support any ban on peas.  

Quality of the ingredients is a real issue.  Good quality grain free food ensures that taurine is added at levels usually higher than actually needed.  Treats with good grains can be added to a pet’s diet as well as directly adding taurine through a supplement. 

So, should you be all of a sudden changing your pet’s food?  Well, no. Many pet parents were put right into a real quandary when this whole thing broke because when they feed their dog grains, the poor things turn into itchy, hot spot messes.  In this case, no, don’t change to a grain inclusive food unless you wish to try something with an ancient grain that would be more friendly for a pet with grain intolerances and see what happens.  If the same happens, then you have no choice but to keep grains out of the diet and then use a taurine supplement.  If you are worried.  I also recommend that instead of changing diets, make up a pot of whole grain brown rice, or quinoa even some organic oats and add that to the meals.  This way you know how the grains were prepared and you can go organic if you wish.  

Here are some other ways your dog can get methionine and cysteine.  Eggs are exceptionally high in methionine and cysteine.  One egg can contain 135 milligrams of cysteine and 190 milligrams of methionine.  So, adding a cooked egg would be a great option and if you look at your pet food bag, if its high quality you will more than likely see eggs as an ingredient.  Spinach is also a good source and can be given to healthy dogs.  There is a slight issue about dogs with kidney issues eating spinach but it would have to be a lot of spinach to cause a problem.  Goats milk!  Goat’s milk is not only a great source of methionine and cysteine, it is also high in taurine.  Well that’s a win, win.  

And I would also like to share something from canadianpetconnection.ca, as they say one friendly word of caution: “Be aware of Veterinary offices (or anyone else for that matter) claiming there is evidence linking certain pet food brands to DCM.  To the FDA’s own admission, there is still no proven connection between any grain-free pet food and dilated cardiomyopathy.  Unfortunately, it has come to our attention that certain vet clinics in North America are taking advantage of their position in hopes of promoting their own veterinary-exclusive products.  Some clinics have even gone as far as demonizing specific popular pet food brands and may be manipulating their clients’ trust for monetary gain.  That’s not to say all Veterinary offices are doing this, but please be aware of anyone using this predatory practice.” 

Well from that, this leads me to my pet peeves section. 

Pet Peeves

The knee jerk reaction and misinformation about DCM has been ridiculous.  And I have to say, I’m quite sick of pet parents coming in saying their vet told them to get off their regular food right now and when I ask why, they say, I don’t know something about it isn’t good for them.  Really!?  Well, vets…you need to do better. And pet parents…do your homework!  For heaven’s sake, veterinarians as professionals should be informed, researched and prepared to explain all aspects to a dog owner as to why they may want to change foods. And I say MAY want to change foods.  When I spoke to my vet that I was tackling this topic he said, oh boy that’s a big one.  And as we spoke he said, yeah, there just isn’t enough information. Well there you go!  And instead of doing a major upheaval of your dog’s food, if you are concerned simply add some healthy grains that you cooked and soothe those fears.  Those grains will provide the methionine and cysteine for taurine absorption and no more worries.  But, as stated in several publications and the FDA itself, millions of healthy dogs worldwide eat a grain free diet so pointing fingers specifically at grain free is just not right. And as I have pointed out, methionine and taurine is added in high quality foods especially grain free as well as eggs and other vegetables to provide natural sources of methionine and cysteine.  And don’t forget that goat’s milk!   As also stated by the FDA, there really isn’t any definitive answer as to how a dog gets DCM.  It is wholly possible that it is a combination of several factors and at this point there isn’t any data to prove one way or the other.  So, my suggestion is be very aware of the word of caution pointed out by canadianpetconnection.ca and be very wary of your vet’s office if they give you no real reason to change food and especially if they direct you to the food they sell.  Hmmm?? That would be rather telltale wouldn’t it?  So, this is exactly the situation I speak about all the time, where your research and your gut instinct for what is best for your pet, needs to be paramount because as I say, knowing is caring. 

Tagged as: DCM,  Pet Food,  pet health.