Many of the foods humans enjoy are not good for pets and some are quite harmful. Raisins and grapes are in this category. Although the toxic principle has not been identified, it appears that the flesh of raisins and grapes contains a poison that causes renal failure in dogs and cats. After ingestion, the animal develops high blood calcium levels that leads to acute renal failure. Once renal failure develops, the prognosis is poor even with therapy.
If your pet ingests grapes or raisins, seek veterinary care immediately. Although not all dogs are susceptible, I always ere on the cautious side and place the patient on intravenous fluids to protect the kidneys. If the patient’s blood analysis looks good after two days of therapy, I breathe a (still cautious) sigh of relief.
I never used to worry about this toxicity in cats, because I never thought a cat would eat a grape or a raisin. Well, I was wrong. I now know of at least one cat who ate raisins and became ill. Please keep grapes and raisins in a secure location to prevent any accidents from occurring. A special note for dachshund owners, dachshunds seem to love grapes so please make sure they do not have access to them.