There is no known toxic dose for grapes or raisins, because different dogs have different reactions. (pets.ca)
Well, the problem with this supplement is research shows that it can reduce appetite, it requires high, potentially toxic doses that can also cause serious side effects. (legionathletics.com)
If it is at all possible, have the product packaging available when you call so the amount ingested can be calculated to determine whether your cat has received a potentially toxic dose. (cathealth.com)