Clinical findings suggest raisin and grape ingestion can be fatal, but the mechanism of toxicity is still considered unknown.
[4] A mycotoxin is suspected to be involved, but none has been found in grapes or raisins ingested by affected dogs.
[8] In some cases, an accumulation of an unidentified golden-brown pigment was found within renal epithelial cells.
Emesis (induction of vomiting) is the generally recommended treatment if a dog has eaten grapes or raisins within the past two hours.
Further treatment may involve the use of activated charcoal to adsorb remaining toxins in the gastrointestinal tract and intravenous fluid therapy in the first 48 hours following ingestion to induce diuresis and help to prevent acute kidney failure.
A negative prognosis has been associated with oliguria or anuria, weakness, difficulty walking, and severe hypercalcemia (increased blood calcium levels).