I Hurt it On The Grape Vine
Grapes, raisins and currants can be toxic to dogs (and possibly cats and ferrets as well).
The Signs
Vomiting and diarrhoea are usually the first signs, often developing within hours of ingestion and the vomitus or stools may contain pieces of the fruit. Other symptoms include abnormal drinking and urination, not eating, abdominal pain and lethargy.