Ask the Vegan Vet: Purines and Urinary Health

Dear Giselle,

Great question! From the Merck Veterinary Manual (MVM, a well-known and accepted veterinary resource): "Dalmatians fed a diet high in animal protein excrete a net acid load in the urine, and urinary ammonium output is subsequently increased. The combined high concentration of ammonium and urate in urine increases the risk of formation of ammonium urate stones. The excretion of acidic metabolites of an animal protein diet is believed to be important in this process, because urinary ammonium excretion is enhanced and ammonium urate is insoluble."

In summary, this means that the animal protein is causing acidic urine with ammonia and increasing their chances of forming urate bladder stones.  Urate stones are a rare type of bladder stone pretty much only seen in Dalmatians (commonly), possibly English Bulldogs and in dogs with liver shunts.  The veterinary diet by Royal Canin (UC Low Purine) to prevent such stones main ingredients are rice, corn, wheat, egg and chicken fat.  So, the only animal protein there is coming from the egg.

MVM continues, "Urine alkalinization minimizes renal ammonia production; the goal is to achieve a urine pH >7."  Vegetarian diets are naturally producing alkaline urine with pH over 7, but caregivers should test at home with urine strips to be sure of this.  They should also try to increase urine volume / more dilute urine by feeding either canned food or adding water to dry food and encouraging drinking water otherwise.

When I looked into vegetable sources of purines, the Mayo Clinic (human of course) notes, "High-purine vegetables. Studies have shown that vegetables high in purines do not increase (emphasis added) the risk of gout or recurring gout attacks. A healthy diet based on lots of fruits and vegetables can include high-purine vegetables, such as asparagus, spinach, peas, cauliflower or mushrooms. You can also eat beans or lentils, which are moderately high in purines but are also a good source of protein. 

So, while peas and lentils may have more purines than other vegetables, it is still much less than animal protein.  If similar to humans, it may not increase the amount of uric acid significantly.  Again, I'd just monitor urine pH to be safe.

Overall message: a vegetarian diet may be best for dogs needing a low-purine diet.

All the best,

Lorelei Wakefield, VMD

---

At v-dog, our pups' health is our #1 priority! V-dog kibble is nutritionally complete, AAFCO approved, and veterinarian endorsed, so you can feel confident that your doggie's diet is top-quality. Our wholesome ingredients are animal-free and sourced from the USA. We've seen thousand of dogs thrive on our kibble since 2005 -- read some of their incredible stories here!

Interested in a plant-based diet for your pooch? Check out our products at v-dog.com!