Updated November 28th, 2020
There’s been talk for some time that certain dog foods could be causing heart disease. I used to think it was a case of vets being biased against grain free and boutique diets. Now I’m not so sure.
This study shows compelling evidence that a nutritionally based, partially reversible cardiomyopathy occurs in some dogs fed non-major brand grain free diets.Journal of Veterinary Cardiology 2019
There is now enough evidence to warn dog owners. Some diets they choose appear to cause a heart disease called dilated cardiomyopathy. These dogs can often be saved with a simple diet change if the cause is recognised early enough.
A Brief History Up To Now
Dilated cardiomyopathy or DCM is a nasty disease where the heart muscle gets weak and thin. We’ve known for a long time that it’s common in Dobermans but we also see it in many giant breeds of dog. The cause has always been assumed to be a genetic fault.
In the 1990s we got the first hints that diets were also a factor. Cardiologists started noticing unexpected breeds like Cocker Spaniels and Golden Retrievers getting DCM, this time related to a taurine deficiency. It wasn’t long before they also noticed that a lot of them were eating the same, unusual foods.
The diets involved were a few boutique brands, all containing lamb or rice. The assumption was made that certain breeds were more sensitive to a faulty diet. Whatever the cause, it seems like those diets were fixed, because for a while things went quiet…
Then in 2018 an unusual spike of DCM cases was noticed. This time, it seems that a wider list of dog breeds are involved and they all have one thing in common: diet. And it isn’t as simple as a taurine deficiency any more.
The Diets Linked With DCM
It’s not just grain-free diets.
Have you noticed how many new brands have appeared on the market in the past ten years? They may contain an unusual ingredient, have a ‘special’ or ’boutique’ feel, or tout the benefit of avoiding grains. These are the sort of diets that the affected dogs are eating.
The term the cardiologists and nutritionists use is boutique, exotic-ingredient, or grain-free (BEG). By this they mean diets which may have one or more of the following features:
- Manufacturing by a smaller company
- Not undergoing feeding trials before sale
- Using potato or pulses (peas, beans, lentils etc) instead of grains
You can read the FDA’s full report here which names the foods most commonly linked with DCM. However, these are only those in the USA.
Suspicion has also fallen on vegan and vegetarian diets. Of course, many BEG diets will be just fine but there’s now a clear link with some of them and DCM. We can expect this problem to exist wherever these foods are sold, including Australia.
The Link With Taurine Deficiency
A long time ago vets realised that taurine is an essential amino acid of cats, and that without it they develop DCM. However, the current situation in dogs is not that simple. Most of the diets from sick dogs have adequate levels of taurine when analysed, and the dogs usually have adequate plasma levels too. Let’s also not forget that, unlike cats, dogs can manufacture their own taurine.
However, it is still true that if we give these dogs taurine supplements, even without changing the diet, many get better. That makes nutritionists suspicious that something in these diets is interfering with taurine metabolism.
It’s also possible that there is an as-yet unrecognised cardiac toxin or deficiency. Diets aren’t just a list of ingredients; once you combine them, unexpected things can happen. Just look at how hard it’s been to work out why so many Australian dogs died of megaoesophagus even though we know the food that did it.
What Dog Owners Should Do
Firstly, don’t panic. The vast majority of dogs on BEG diets will remain perfectly healthy. However, personally I would be moving to a larger manufacturer that conducts feeding trials.
What I would not recommend is a wholesale move to home-made diets. I’ve published what I believe to be a balanced home made diet, but I still believe that these are not a good idea for the majority of dog owners. How many will invest in the vitamin and mineral supplements needed for balance, and how many have the storage space and time? Some, yes, but not all.
And then there’s the fact that we still have the issue of using an untested diet.
For owners of dogs with DCM, the big message is this: ask your vet for a taurine supplement. We can’t test which dogs need taurine, so we should be giving it to all dogs with DCM. I’d even give it to Dobermans. We aren’t sure of the correct dose, but here are some guidelines:
|Body Weight||Suggested Taurine Dose|
|Under 10kg||250mg twice daily|
|10 to 25kg||500mg twice daily|
|Over 25kg||1000mg twice daily|
Taurine should be safe and harmless when given to normal dogs. Then if your dog is lucky enough, the prognosis for this special type of DCM can be quite good. However, I fear that many dogs with DCM died without anyone asking what they were eating.
If you’re reading this, not any more. Pass it on!
Related: The Pros & Cons Of Grain-free Diets
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. These blogs are from a series regularly posted on email and Twitter. Subscribe via email here to never miss a story!
Have something to add? Comments are welcome below and will appear within 24 hours.
Adin, D., DeFrancesco, T. C., Keene, B., Tou, S., Meurs, K., Atkins, C., … & Saker, K. (2019). Echocardiographic phenotype of canine dilated cardiomyopathy differs based on diet type. Journal of Veterinary Cardiology, 21, 1-9.
Freeman, L. M., Stern, J. A., Fries, R., Adin, D. B., & Rush, J. E. (2018). Diet-associated dilated cardiomyopathy in dogs: what do we know?. Journal of the American Veterinary Medical Association, 253(11), 1390-1394. Full text.