Most people by now are aware that grapes can be toxic to dogs, but no one ever knew why. Grape juice wasn’t a problem. Grape flavored candy wasn’t an issue. But grapes and raisins were causing acute kidney failure in some dogs. We’ve made quite a few dogs vomit because they ate a bunch of grapes or raisins.
Three veterinarians, (two that work for the SPCA Poison Control) think they have it figured out and recently published a letter in the Journal of the American Veterinary Medical Association. A dog was presented to a vet for eating a lot of homemade playdough. Eating playdough can cause a lot of drinking, urinating, weakness, disorientation, and other signs of excessive sodium in the blood because homemade playdough contains a large amount of salt. A main part of treatment is large volumes of intravenous fluids. But in this dog’s case, the owner didn’t use much salt when making the playdough. The dog didn’t have the expected high levels of sodium in his blood, but he did have signs of severe, acute kidney failure. This is not expected with high doses of sodium, so something else had to be going on.
Homemade playdough also contains cream of tartar, which contains potassium bitartrate, the potassium salt of tartaric acid. Tartaric acid has a wide margin of safety in humans and lab animal models. Signs of tartaric acid poisoning include vomiting, excessive drinking, and acute kidney failure. The toxicologists had a “light bulb moment” where they realized that tartaric acid and potassium bitartrate are present in high concentrations in grapes. Older research articles mention that dogs are sensitive to tartaric acid and develop acute renal failure. No one ever put this together because dogs that eat homemade playdough end up on IV fluids, which is the treatment for acute kidney failure!
More research will be done to verify this hypothesis, but it seems like the mystery has been solved. So definitely continue to keep grapes and raisins away from your dogs, but watch them when you are making homemade playdough, meringue, Snickerdoodles or other yummy baked goods!
By Dr. Scarlett
