No — grapes can cause kidney failure in dogs.
Grapes (and raisins) can trigger sudden kidney failure in dogs, and scientists still don't know exactly which compound is responsible — or why some dogs are more sensitive than others. There is no known safe amount. If your dog ate grapes, call your vet immediately, even if they seem fine.
If your dog already ate this, don't wait for symptoms — call your vet now, or the ASPCA Poison Control line at (888) 426-4435. Note what and how much was eaten.
Get the printable list of the 30 most dangerous foods for dogs.