The full answer
Grapes and the dried fruit made from them (raisins, sultanas and the small dried Zante currants used in baking) belong to the Vitis genus. Veterinary toxicology references link eating them to acute kidney injury in dogs, which can progress to kidney failure.
Not every dog that eats grapes gets ill, and the effect varies from one time to the next. Because nobody fully understands why, veterinary sources don't treat any amount as reliably safe. Tartaric acid has been proposed as the cause, but that's still a proposal, not settled fact.
According to the Merck Veterinary Manual, vomiting or diarrhoea usually starts within 6–12 hours, and kidney failure can develop within one to three days. Once a dog stops producing urine the outlook is poor, which is why veterinary sources advise getting help early, before any signs appear.
The fresh berries of the Ribes genus (blackcurrants, redcurrants and white currants) are different plants, and the Merck Veterinary Manual notes they haven't been linked to kidney injury. This page doesn't rate them. If you're not sure which fruit your dog ate, treat it as a grape product and call a vet.
Are Grapes Good for Dogs?
There is no benefit that justifies the risk. Any nutrient in grapes is available from foods that are not associated with kidney injury in dogs.
Risks and Things to Know
- Associated with acute kidney injury, which can progress to kidney failure and be life-threatening
- The effect is unpredictable — not every exposed dog becomes ill, and no amount is known to be safe
- Raisins, sultanas and Zante currants are concentrated and appear in many baked goods
- Hidden sources include fruit cake, trail mix, cereal bars, hot cross buns and mince pies
- First signs can be delayed by hours, and kidney damage by one to three days
How much is okay?
There's no safe amount. Grapes and dried grapes shouldn't be fed to dogs in any quantity.
Keep grapes, raisins and baked goods containing them well out of reach, including in bags and lunchboxes.
How Should I Prepare It?
- None — this food should not be prepared for dogs.
- Check ingredient lists of baked goods and snack bars before sharing anything with your dog.




