My dog just ate half of my raisin bagel. Is this toxic?

Simply put, yes. Grapes and raisins cause an indiosyncratic toxicosis in dogs. This means that we don’t know what the mechanism of toxicosis is and not all dogs are sensitive to the toxicity. Because we cannot predict which dogs will experience the toxicity and because it does not appear to be dose-related, the recommendation for any grape or raisin ingestion is to be seen immediately by a veterinarian. Treatment consists of inducing vomiting, administration of activated charcoal, and 48 hours of hospitalization with IV fluids. These treatments are used to try to prevent the toxicity which causes acute kidney failure which can be fatal. In most, if not all cases, appropriate treatment results in an excellent prognosis for the pet.