Grapes and raisins are great human treats, but should be avoided when it comes to our furry friends. The level and cause of toxicity in grapes and raisins is unknown, making this food an even greater concern. There is no exact threshold for toxicity, so while it might be okay for a large breed dog to eat a single grape, it might be life-threatening for a small breed. Some studies even suggest that likelihood of grape or raisin poisoning varies from animal to animal, regardless of amount or breed. Grapes and raisins most commonly cause kidney failure in dogs, and because of this, the same is considered a potential concern in cats. Signs can be seen anywhere from 6-24 hours after ingestion. Vomiting is seen in almost all cases, with other signs including diarrhea, decreased appetite, pain in the abdomen, lethargy, weakness, sweet smelling breath, decreased urination, and dehydration. For the time being, grapes are classified as a moderate risk, but it should be considered an emergency for any small animals or any large quantities.