Why grapes are dangerous for dogs
Grapes, raisins, sultanas, and currants can cause sudden acute kidney failure in dogs. The toxic agent is now believed to be tartaric acid, but sensitivity varies enormously — some dogs eat a grape with no effect, while others develop kidney failure from just a few. Because you can't predict how your dog will react, all grape and raisin ingestion is treated as potentially serious.
What to do if your dog ate grapes
Don't wait for symptoms. Call your vet or a pet poison line right away: ASPCA Animal Poison Control (888) 426-4435 or Pet Poison Helpline (855) 764-7661 (US). Early decontamination (inducing vomiting) and IV fluids dramatically improve the outcome. Use our grape & raisin checker to gauge the risk by your dog's weight while you call.
Symptoms of grape poisoning
- Vomiting (often within a few hours) and diarrhea
- Lethargy, weakness, loss of appetite
- Abdominal pain
- Reduced or no urination as the kidneys are affected (24–72 hours)
Frequently asked questions
My dog ate one grape — should I worry?
Most large dogs tolerate a single grape, but because some dogs are highly sensitive, it's safest to call your vet or poison control for advice based on your dog's size.
Are raisins worse than grapes?
Yes — raisins are dried and far more concentrated, so a smaller number delivers a more dangerous dose.
What about grape juice, jelly, or wine?
Avoid all of them. Grape products can be risky and may add other dangers like alcohol or xylitol.
Related: grape toxicity checker · full food checker · safe berries.