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FAQs on Calcium Oxalate Stone in Dogs

Posted on by Kristina Johansen

Learning that your dog has calcium oxalate stones can leave you with a lot of questions. This FAQ answers some of the most common ones. For a deeper dive into calcium oxalate stone and dietary management, see my full guide here: Diet for Calcium Oxalate Stones in Dogs.

If your dog is prone to calcium oxalate stones, you need to avoid foods high in oxalate, such as spinach, carrots, sweet potatoes, brown rice, organ meats, nuts and tofu.
There isn’t a single, definitive list of oxalate values for foods. Levels can vary depending on where and how a food is grown, the plant variety, and even how it’s prepared - for example, boiling can reduce oxalate content. Different studies also measure oxalate in different ways. Two widely used references are the Harvard Oxalate Food List and the University of California, Irvine Kidney Stone Center tables, both of which provide well-researched guidance.
A diet with normal calcium, reduced salt, moderate protein, and low oxalate tends to work best. Wet or home-prepared diets are generally preferable to dry ones, as they help increase water intake and dilute the urine, which is crucial for reducing stone formation.
Calcium oxalate stones have a high recurrence rate, so feeding the right diet is absolutely key. The aim is to create urine conditions that discourage stone formation by limiting oxalate, avoiding excess calcium absorption, keeping protein and sodium at moderate levels, and maintaining a urine pH that doesn’t favour calcium oxalate. Regular monitoring and sticking with the diet are also essential to minimise the risk of recurrence.
Low oxalate foods can be used as treats for oxalate stone-forming dogs, such as most lean meats, poultry, eggs, cauliflower, apples (peeled), strawberries, blueberries, cucumber and melon (all types).
No. Unlike some other bladder stones, calcium oxalate stones cannot be dissolved with diet alone. They usually require surgical removal or other veterinary procedures. However, diet plays a key role in preventing recurrence.
Yes, absolutely! A homemade diet is often more effective due to its higher water content and the personalised inclusion of minerals it provides. However, it needs to be appropriately balanced and follow the recommended stone-prevention guidelines.
Very high-protein diets may acidify urine, which increases the risk of calcium oxalate stones. Most dogs with a history of stones do better on moderate protein tailored to their health and activity.
No, calcium should not be avoided. Dogs need calcium for healthy bones, muscles, and many other body functions. In fact, providing the right amount of calcium is important because it helps bind oxalate in the gut so it can leave the body in the stool. Too little calcium can actually increase the risk of stones. The key is to feed a diet with a normal, balanced amount of calcium - not too little and not too much.
When urine is too acidic (below pH 6.5), calcium oxalate stones are more likely to form. Keeping the urine closer to neutral, around pH 7, with the right diet and supplements can help lower the risk of stones coming back.
Potassium citrate can help by making urine less acidic, thereby lowering the chance of stone formation. However, it should only be used under professional guidance.
Calcium oxalate stones form when calcium and oxalate in the urine bind together, especially if the urine is too acidic or these compounds are present at high levels. Normally, a natural protein called nephrocalcin helps prevent this by blocking the crystals from forming. In some dogs, nephrocalcin doesn’t work properly, often due to genetics, so stones are more likely to develop.
Yes - peanut butter is high in oxalate, which can increase your dog’s risk of forming kidney stones.

I hope this FAQ has helped answer some of your questions. If you’d like support with your dog’s diet, please get in touch. I’d be happy to help. You can also return to my full guide on Diet for Calcium Oxalate Stones in Dogs for more detailed information.

About the author:

Kristina Johansen, PGCert, MSc Animal Nutrition (cand.) is a pet nutritionist with over 15 years of experience. She specialises in home-prepared dog diets that meet NRC guidelines. Learn more →