Grape Poisoning in dogs – Have we solved the mystery?

Can Dogs Eat Grapes?
Grape poisoning in dogs has long been a mystery to the veterinary field. While documented cases of dogs developing kidney damage after ingesting grapes existed, even the experts could not figure out why.
Recently, the ASPCA Animal Poison Control Center made a discovery about grapes that may have solved this question!
Why are grapes toxic to dogs?
We initially believed that pesticides or fungal contamination were possibly responsible for the toxicity of grapes. However, a recent discovery by the ASPCA found that a homemade play-doh caused the same type of kidney damage. Cream of tartar was the main ingredient in this play-doh. With research, the ASPCA toxicologists found that tartaric acid was present in the composition of some grapes in a fairly high concentration. Similarly, tartaric acid was missing from grape jelly, grape juice, and wine – none of which cause grape poisoning in dogs.
What is tartaric acid?

Tartaric acid, also known as cream of tartar or potassium bitartrate, is a byproduct of grape fermentation made during the process of winemaking. Bakers frequently use it to stabilize egg whites and cream. It is also a leavening agent that helps batters and doughs to rise.
Tartaric acid works as a great natural cleaner when added to lemon juice or vinegar. Unluckily for the poor dog who got into the homemade play-doh, cream of tartar is a staple in many play-doh recipes.
How many grapes will cause grape poisoning in dogs?
Unfortunately, the tartaric acid content of grapes varies by grape type, vine location, and growing conditions. Since many of the grapes we buy from the store don’t have a recorded amount of tartaric acid, we still cannot determine how many grapes will poison a dog. Thus, while we’ve started on the first step to solving the mystery of grapes, the treatment remains mostly the same.
Are grapes toxic to cats?
So far, there have not been any recorded cases of cats that developed kidney failure after eating grapes. This does not mean that cats are unaffected! It may mean we simply have not seen it. However, it is possible that grapes may not be as poisonous to cats as they are to dogs. That being said, all cats who ingest grapes should be evaluated by animal poison control or a local vet.

What about other things that contain tartaric acid?
With this new knowledge about grape toxicity in dogs, we can take additional steps to prevent poisoning due to other similar substances. If your pet has ingested any of the following, they may be at risk:
- Grapes
- Raisins
- Currants
- Cream of tartar-based recipes, including play-doh
- Tamarinds or tamarind paste
How is grape poisoning in dogs treated?
Treating grape poisoning remains the same:
- Inducing vomiting within 2-4 hours to retrieve as many grapes as we can.
- The longer we wait to induce vomiting, the fewer grapes we can get back.
- The longer we wait to induce vomiting, the fewer grapes we can get back.
- +/- Activated charcoal administration.
- There is some debate in the veterinary field as to whether this is needed and helpful.
- There is some debate in the veterinary field as to whether this is needed and helpful.
- IV fluid therapy for 48 hours.
- This will flush and protect the kidneys from damage
- This will flush and protect the kidneys from damage
- Repeated bloodwork to monitor the status of the kidneys
My dog ate grapes, is he going to live?
Most dogs who receive prompt, aggressive treatment with emesis and fluid therapy do very well after the ingestion of grapes. Dogs who do not receive treatment at the time of exposure and instead show up to the clinic with kidney problems and trouble urinating do not recover as well.
Thus, immediate veterinary care for dogs with suspected grape exposure is extremely important. If you believe your dog has been exposed to a substance containing tartaric acid, contact the animal poison control center.