Oxalates & Dogs: Should You Be Paying Attention?

Oxalates & Dogs: Should You Be Paying Attention?

By Leslie Ors, RN, Certified Professional Canine Nutritionist

Dogs evolved eating prey—not spinach.

While wild canines occasionally consume plant matter, they naturally eat a diet that’s remarkably low in oxalates.

Today, many modern dog foods contain ingredients like potatoes, sweet potatoes, spinach, peas, and legumes, dramatically increasing the amount of oxalates our dogs consume.

Does that matter?

I believe it deserves a closer look.

What Are Oxalates?

Oxalates (also called oxalic acid) are naturally occurring compounds found in many plants. They help protect plants from insects and grazing animals and are completely normal components of many fruits and vegetables.

When eaten, oxalates can bind to minerals such as calcium, iron, magnesium and B6 inside the digestive tract limiting the uptake of these nutrients. Research has also shown that oxalates can contribute to overall inflammation, GI issues and autoimmune disease.

Research shows that excessive oxalate intake has multiple adverse effects. It directly and indirectly impairs our natural immune defenses by disrupting intracellular control, damaging circulating immune cells, inflaming mucosal tissues, and driving chronic oxidative stress. At the same time, it allows pathogens to thrive by altering the gut microbiome.

For thousands of years, canines survived on:

• Prey

• Bones

• Organs

• Fish

• Eggs

The result?

A naturally low-oxalate diet.

High-oxalate plants simply weren’t (and still aren’t) a regular part of their menu.

Modern dog food changed that.

Many commercial dog foods rely on plant ingredients like:

• Sweet potatoes

• Potato starch

• Peas

• Lentils

• Spinach

Spinach deserves special mention because it’s often marketed as one of the healthiest vegetables available.

While spinach contains valuable nutrients on paper, it is also one of the richest dietary sources of oxalates. Those oxalates bind minerals—including calcium—which can reduce how much is actually absorbed by the body. For that reason, I generally choose lower-oxalate vegetables that provide similar nutritional benefits without the same oxalate burden.

The above ingredients are also often used as carbohydrate sources or fillers.

That means today’s dogs may consume far more oxalates than their ancestors ever would have.

High dietary oxalate can contribute to the formation of calcium oxalate bladder and kidney stones.

Researchers continue to explore how excess oxalates may influence inflammation and oxidative stress, create a negative impact on joint health and contribute to auto-immune disease like hypothyroid since oxalates tend to accumulate in thyroid tissue

One thing we do know for sure:

Dogs have no nutritional requirement for high-oxalate vegetables.

Beyond bladder stones, I believe it’s worth asking a bigger question:

Why ask the body to manage compounds it was never designed to consume in large amounts?

Every compound the body has to bind, transport, neutralize, or eliminate requires energy and resources. By choosing foods that are naturally lower in oxalates, we’re simply asking the body to do less unnecessary work.

I often think of it as building a more resilient terrain.

Instead of constantly managing excess dietary compounds, the body can devote more of its resources toward maintaining healthy joints, connective tissue, the immune system, and normal cellular repair.

That’s a philosophy I apply not only to dogs with urinary issues, but to healthy dogs as well.

Dogs May Benefit From a Lower-Oxalate Diet

While the strongest evidence for reducing dietary oxalates is in dogs prone to calcium oxalate bladder stones, I believe many healthy dogs may also benefit from a naturally lower-oxalate diet.

Since oxalates can bind minerals such as calcium, iron and magnesium, potentially reducing how much is available for the body to absorb, choosing lower-oxalate foods may help maximize nutrient availability while reducing unnecessary metabolic work.

When we’re trying to reduce inflammation & support healthy joints, connective tissue, immune function, and overall resilience, every small advantage matters.

Reducing dietary oxalates may be beneficial for dogs that:

• Have a history of calcium oxalate bladder stones

• Have experienced recurrent urinary crystals

• Have previously undergone surgery for calcium oxalate stones

• Are genetically predisposed to forming calcium oxalate stones

• Have allergies or overactive immune system

• Have GI issues or chronic diarrhea

• Have joint disease

• Have autoimmune disease like hypothyroid

Foods Naturally High in Oxalates

Many healthy vegetables contain oxalates. That doesn’t make them “bad”—it simply means they may not be ideal as everyday consumption.

Examples include:

• Spinach

• Swiss chard

• Beet greens

• Beets

• Sweet potatoes

• White potatoes

• Rhubarb leaves

• Kale

• Buckwheat

• Kiwi

• Soy

• Beans

• Peas

The majority of commercial pet foods may contain several of these ingredients, particularly grain-free recipes that rely heavily on potatoes or sweet potatoes. Because manufacturers generally do not publish oxalate content, it’s difficult to know the total oxalate load of a finished food.

Lower-Oxalate Vegetables I Prefer

When preparing Bella’s meals, I tend to rotate vegetables that are naturally lower in oxalates.

Some of my favorites include:

• Cucumbers

• Zucchini

• Summer squash

• Winter squash

• Berries

• Melons

• Cauliflower

• Mushrooms

• Carrots

• Romaine lettuce

• Arugula

• Fresh herbs such as dill, cilantro and basil

These fruits & vegetables provide valuable vitamins, minerals, antioxidants, and fiber while keeping oxalate intake relatively low.

Why Fresh Feeding Gives You More Control

One of my favorite things about preparing fresh food is that I know exactly what’s going into Bella’s bowl.

Instead of relying on a single vegetable ingredient used in every meal, I can rotate ingredients based on seasonality, nutrient diversity, and Bella’s individual needs.

That flexibility simply isn’t possible with most commercial diets.

Fresh feeding allows you to:

• Rotate vegetables regularly

• Adjust ingredients for specific health concerns

• Increase moisture naturally

• Choose whole-food nutrition over relying on fixed formulas

My Philosophy

I don’t believe in fearing foods.

I believe in understanding them.

Spinach isn’t poisonous.

Sweet potatoes aren’t “bad.”

Every food has strengths, limitations, and situations where it makes more—or less—sense.

For Bella, I simply choose vegetables intentionally, rotate them often, and focus on fresh, minimally processed ingredients whenever possible.

My goal isn’t to eliminate every molecule of oxalate.

It’s to create a diet that’s as biologically appropriate as possible.

Dogs evolved eating prey—not spinach smoothies.

When I have the opportunity to choose between two equally nutritious vegetables, I’ll almost always choose the one that’s naturally lower in oxalates. It’s a simple way to work with the body rather than asking it to continually process compounds it doesn’t nutritionally require.

Key Takeaways

✔ Oxalates are naturally occurring compounds found in many plants.

✔ Dogs evolved eating a naturally low-oxalate diet centered around prey, organs, bones, fish, and eggs.

✔ Dogs prone to calcium oxalate bladder stones may benefit from limiting high-oxalate ingredients.

✔ Fresh feeding allows you to rotate ingredients and tailor nutrition to your dog’s individual needs.

✔ Hydration, balanced nutrition, and overall urinary health remain just as important as oxalate intake.

At Two Tails Canine Wellness, I believe nutrition should empower—not overwhelm. The more we understand about the foods we feed, the better decisions we can make for our dogs’ long-term healths.