ANY amount can be toxic — there is no established safe dose.
IMPORTANT: ANY grape/raisin ingestion by a dog should be treated as an emergency. Call your vet immediately.
Grapes and raisins can cause acute kidney failure in dogs. The toxic substance was recently identified as tartaric acid. There is NO established safe dose — some dogs develop kidney failure from a single grape, while others seem unaffected. This individual variability makes ALL grape/raisin ingestion an emergency. Raisins are more concentrated and potentially more toxic per gram. Symptoms: vomiting within 6-12 hours, lethargy, diarrhea, decreased urination, abdominal pain. Treatment must begin IMMEDIATELY: induce vomiting (within 2 hours), activated charcoal, aggressive IV fluid therapy for 48-72 hours. Without treatment, kidney failure can be irreversible and fatal. This applies to all grape products: juice, wine, currants, sultanas.