Ingestion of grapes, raisins, sultanas or currants (fresh and dried Vitis vinifera fruits) can cause renal failure in dogs and possibly also in cats, ferrets and skunks. This article outlines the sources of poisoning and the clinical signs, and discusses toxic dose and treatment. The toxic mechanism remains unclear and, although many animals eat these fruits without adverse effect, it is not possible to determine which are at risk. Treatment is therefore recommended in all cases and is aimed at gut decontamination, protecting the kidneys and maintaining urine output. Prognosis is good if aggressive fluid therapy for 48 hours is started before the onset of renal impairment, but is poor in dogs with oliguria or anuria.