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Facts about Grain-Free Foods & Taurine Deficiencies

You’ve likely read the stories about a possible link between grain-free foods and canine heart disease … specifically dilated cardiomyopathy (DCM).

This started with a 2018 FDA announcement that they were investigating these foods. As of a November 2020 announcement, the investigation continues, without any real conclusions. The latest information was presented at a September 2020 forum hosted by Kansas State University. You can read some of the papers here.

So, what does this have to do with lectins? It’s quite a long explanation, but stay with me …

Grain-free foods started as a marketing ploy by the pet food industry. Consumers realised that dogs don’t need grains in their diets. So they wanted grain-free foods.

But you can’t make kibble without starch. That’s what holds it together. So the industry found an alternative starch … in the form of legumes and potatoes. (Yes, these are high lectin foods.) And they promoted these diets as grain-free.

DCM And Taurine

Grain-free foods are the main target of this FDA investigation. Taurine deficiency can be one cause of DCM. The FDA suspects these diets don’t provide sufficient taurine for dogs. But they do admit that there are many possible causes of DCM … so they haven’t pinpointed the reason for DCM cases. They’re not even shore it has anything to do with diet.

But let’s talk a bit about taurine, because lectins are an important factor! Here’s a bit of history about taurine in pet foods.

Taurine In Pet Foods

The link between DCM and taurine was first discovered in cats in the 1970s. Cats were developing heart disease. That’s because, unlike dogs, cats can’t manufacture taurine. So they need it in their diets. They weren’t getting enough taurine from their starchy commercial diets. So manufacturers started adding taurine to the diets. Taurine is considered an essential amino acid for cats. So supplementing with taurine solved the problem.

Fast forward to 2003-2005. Researchers found some dog breeds had DCM caused by taurine deficiency. Newfoundlands, Golden Retrievers and American Cocker Spaniels all had DCM and low blood taurine levels. The dogs recovered when they were given taurine supplements.

So that’s why the FDA and other researchers think grain-free diets could be part of the problem. There could be something to that theory.

How Taurine Works In Dogs

Taurine is an amino acid. It’s considered non-essential for dogs … because they make taurine themselves. But to make taurine, your dog’s body needs two other amino acids: methionine and cysteine.

Methionine and cysteine are plentiful in many meats, as well as eggs and fish. So why would swapping grains for legumes and potatoes cause a taurine deficiency? There are lectins in grains too, aren’t there?

But here’s the difference.

Legumes Vs Grains In Dog Food

The grains in dog food do have lectins. But they’re low in protein. And legumes like lentils, peas or beans are much higher in protein than grains.

So … adding these foods instead of grains allowed manufacturers to use more plant proteins. That allowed them to cut back on more expensive animal proteins.

Using legumes isn’t just about marketing … it’s about bigger profits too!

So because there’s less meat … these foods have lower levels of methionine and cysteine. And that means dogs don’t get these building blocks to make taurine.

And it’s not just that there’s less methionine and cysteine in the food. The problem is compounded because ... Lectins also stop dogs absorbing methionine and cysteine. Again, dogs need these to make taurine. AND … inflammation from lectins may stop dogs from producing taurine as well.

Do Lectins Cause DCM?

Well … the FDA is still investigating. So we don’t officially know. But there’s good reason to be suspicious of the effects of these lectin foods on your dog’s taurine production.

Poultry, beef, fish, eggs and organ meats are all rich in taurine. Feed your dog a diet with plenty of animal proteins … and he won’t have a taurine deficiency. (Sadly I can’t promise he won’t get DCM, because there could be other reasons for that.)

Lectins Increase Glyphosate Exposure

This isn’t a direct health effect of lectins. But it’s impossible to talk about lectins without considering it. Many high lectin foods are contaminated with the pesticide glyphosate (Roundup).

I mentioned GMOs already. And you might notice there’s some overlap. Many high-lectin grains and legumes are foods that are often genetically modified (GMO) … like wheat, corn or soy.

And that means these crops are sprayed with the weedkiller glyphosate. But it’s not just GMOs. Other crops are sprayed with glyphosate as a dessicant, to dry them before harvesting. These include …







In fact, testing by researchers at HRI Labs shows the OWL foods are the very highest in glyphosate. OWL stands for oats, wheat and legumes. And those 3 categories include other grains like barley and rye … plus legumes like lentils, chickpeas and beans. They’re all high-lectin foods!

HRI Labs has also shown that dogs have 30 times more glyphosate in their bodies than the average human! And even more than horses and cats. That’s likely because kibble contains massive levels of glyphosate. Kibble has 200 to 600 parts per billion (ppb) of glyphosate. That’s compared to raw dog food at only 5 ppb. So kibble-fed dogs are getting whopping amounts of glyphosate in their food.

Why Avoid Glyphosate

You don’t want your dog to eat glyphosate. The WHO has said that glyphosate is …

A probable human carcinogen

A known animal carcinogen

So glyphosate can increase your dog’s risk of cancer. Not to mention many other health risks:

Interferes with gut bacteria

Damages the gut lining, causing leaky gut

Harms kidney function, can cause kidney disease

By disrupting gut bacteria, weakens the immune system

Is linked to autoimmune disease and chronic inflammatory diseases

There are ways to deactivate or block lectins. But you can’t get glyphosate out of food. So glyphosate is another big reason to avoid giving your dog high-lectin foods. And raw dog foods have tiny amounts of glyphosate. So a raw diet is your best choice.

If you do feed kibble, try to find one that’s organic. Organic foods have 95% less glyphosate.

So … what can you safely feed your dog to avoid lectins?

What To Feed Your Dog

So by now you may be wondering what you should feed your dog. Even some meats could have lectins!

But most meats are low in lectins. And they have plenty of taurine, as well as other nutrients that support your dog’s health.

If you’re already feeding a raw meat-based diet, your dog’s food will be low in lectins. Remember that pasture-raised meats are best if you can get (and afford) them. Animals fed a lot of grains could contain some lectins.

You can safely feed some fruits and veggies. They contain valuable nutrients that benefit your dog’s health.

Avoid These Foods



Nightshade veggies

A1 dairy

Feed These Foods

Raw meats and organ meats – pasture raised if possible

Free range eggs

Wild caught fish


Dark leafy vegetables

It’s best to try to avoid high-lectin foods in your dog’s diet. If you do give your dog some grains or legumes, or you feed a grain-free kibble … you’ll want to read how to limit the damage in the next section.

How To Limit Lectin Damage