Grape, raisin and sultana poisoning
Why are grapes and dried grapes toxic?
Grapes, raisins, sultanas and Zante currants can cause acute kidney injury in dogs. Tartaric acid and its salt, potassium bitartrate, are currently considered the most likely toxic components, but the amount present varies between fruits and products.
Dogs also differ in their sensitivity. A quantity that causes no illness in one dog may cause severe kidney damage in another, so there is no reliably safe number of grapes or raisins.
Tamarind and cream of tartar also contain tartaric acid and can cause a similar toxicity. Evidence is strongest in dogs; grape-related kidney injury has not been well documented in cats, but veterinary advice is still recommended after feline exposure.
What products are included?
• Fresh red, green, seeded or seedless grapes
• Raisins and sultanas
• Zante currants, which are dried grapes
• Foods containing dried grapes, such as fruit cake, hot cross buns, muesli, trail mix and raisin bread
• Tamarind and cream of tartar
True currants from the Ribes plant group, such as blackcurrants and redcurrants, are different fruits and have not been associated with this kidney toxicity. Mixed foods may still contain other harmful ingredients, including chocolate, xylitol, alcohol or macadamia nuts.
What signs might I see?
Some dogs remain well initially. Gastrointestinal signs commonly develop within 6-24 hours, while evidence of kidney injury may appear over the following one to three days.
• Vomiting, often the earliest sign
• Diarrhoea, drooling or abdominal discomfort
• Reduced appetite, lethargy or weakness
• Increased thirst and urination
• Dehydration or wobbliness
• Reduced urine production or inability to pass urine as kidney injury progresses
• Tremors or seizures in severe cases
Do not wait for clinical signs. By the time reduced urine production develops, kidney injury may already be severe.
What should I do immediately?
• Remove any remaining fruit or food and prevent further access.
• Record what was eaten, the largest possible amount and the approximate time.
• Keep the packaging or ingredient list and bring it to the hospital.
• Contact your veterinarian or nearest emergency hospital immediately.
Do not induce vomiting at home unless specifically directed by a veterinarian or veterinary poison specialist. Home methods can cause aspiration, injury or additional poisoning.
How is the risk assessed?
Diagnosis and risk assessment are based on the history of exposure, the amount and type of product, your dog’s body weight and any clinical signs. There is no test that directly measures grape toxin in the body.
Blood and urine tests are used to assess kidney function, hydration and electrolytes. Initial results may be normal soon after ingestion, so repeat testing over the next 48-72 hours may be recommended.
How is it treated?
There is no specific antidote. Treatment focuses on removing fruit before more toxin is absorbed and protecting kidney function.
• Inducing vomiting after a recent ingestion, provided the dog is alert and it is safe to do so
• Intravenous fluid therapy could be considered in patients requiring rehydration or if unwell
• Anti-nausea medication and other supportive care
• Regular blood tests to monitor kidney values and electrolytes
• Close measurement of urine output, hydration and blood pressure
• A urinary catheter in selected patients when accurate urine measurement is essential
The benefit of activated charcoal for grape and raisin exposure is uncertain, so it is not automatically required and is considered case by case.
Dogs that develop severe kidney failure and stop producing urine may require referral for haemodialysis or another form of renal replacement therapy, where available.
Will my dog need hospitalisation?
Hospitalisation recommendations depend on the amount and type ingested, whether vomiting successfully removed the fruit, the time since exposure and the dog’s clinical condition. Dogs with a large or uncertain exposure, spontaneous vomiting or diarrhoea, abnormal test results, or other risk factors commonly require intravenous fluids and monitoring.
What is the outlook?
Dogs treated promptly before kidney abnormalities develop generally have a good prognosis. The outlook becomes more guarded once kidney values rise and is poor when urine production becomes markedly reduced or stops.
Some survivors of acute kidney injury may be left with chronic kidney disease and require ongoing monitoring.
Prevention
• Never intentionally feed grapes, raisins, sultanas or foods containing them to dogs.
• Keep baked goods, lunchboxes, handbags, compost and rubbish securely out of reach.
• Check ingredient lists in fruit breads, cakes, cereals and snack mixes.
• Ensure children and visitors know these foods are unsafe for dogs.
Clinically reviewed and approved by Dr Giulia Agostini, Pet Emergency Senior Veterinarian and Clinical Manager, DVM MANZCVS (ECC) August 2026