Macadamia nuts have been included in the top foods to avoid feeding dogs. Like grapes or raisins, the substance of the nut responsible for negative reactions is unknown. Minuscule amounts of the nut can cause adverse reactions...
Any dogs can be affected, however some dogs seem to tolerate grapes and raisins without a problem. Clinical signs of toxicity may start a few hours after ingestion and include vomiting, diarrhea, lethargy, poor appetite, and decreased urine production. Immediate medical care is necessary to try to prevent permanent kidney damage.
ll types of grapes whether red or green, cooked, seedless, peeled, dried, or fresh can be toxic to dogs, even in small amounts. Grape toxicity is linked to kidney damage.

The short answer to the question, Can dogs eat grapes? is no. Grapes and raisins are toxic to dogs and can cause serious health issues, including kidney failure. No. Dogs cannot eat peeled or seedless grapes or raisins which are dried grapes in any amount. The exact cause of grape toxicity in dogs after they ingest a grape is not known. Dogs should never eat grapes in any form, quantity, or variety. Grapes and raisins are known to cause acute kidney failure in dogs, and since the exact toxic compound remains unknown, there is no safe amount for consumption. No, dogs cannot eat grapes or raisins because they are considered toxic. Grapes and raisins contain tartaric acid, which dogs cannot digest. Exposure to these foods can cause: Vomiting Increased... Any dogs can be affected, however some dogs seem to tolerate grapes and raisins without a problem. Clinical signs of toxicity may start a few hours after ingestion and include vomiting, diarrhea, lethargy, poor appetite, and decreased urine production. Immediate medical care is necessary to try to prevent permanent kidney damage.
No. Dogs cannot eat peeled or seedless grapes or raisins which are dried grapes in any amount. The exact cause of grape toxicity in dogs after they ingest a grape is not known.

Dogs should never eat grapes in any form, quantity, or variety. Grapes and raisins are known to cause acute kidney failure in dogs, and since the exact toxic compound remains unknown, there is no safe amount for consumption.
Unfortunately is it not safe to feed your pets, especially dogs, grapes, raisins and sultanas. The cause of this toxicity is, as far, unknown, but there have been researched findings that the ingestion of grapes and their derivatives, are known to cause renal failure in our domestic house pets.