Dog Ate Grapes or Raisins? Toxicity Calculator
Written for general planning, not medical advice — no one at Argos Paws is a veterinarian. If something is wrong with your dog right now, call your vet or the nearest emergency clinic.
Quick answer: the Merck Veterinary Manual says more than one grape or raisin per 10 lb (4.5 kg) of body weight may be enough to damage a dog's kidneys — that's 2 for a 20 lb dog. But the toxin level varies from fruit to fruit, so no amount is known to be safe. If your dog ate any grapes, raisins, sultanas, or currants, call your vet; within about 2 hours they can often just make your dog sick.
A guide to urgency, not a diagnosis. Some dogs react to fewer grapes than this, and you can't tell in advance which ones will.
How many grapes are toxic to a dog? Chart by weight
The number of grapes or raisins at which Merck's risk level is reached. Treat these as "call the vet now" lines — not as safe limits below them.
| Dog weight | Grapes or raisins at the risk level |
|---|---|
| 5 lb (2.3 kg) | More than a single one (any amount) |
| 10 lb (4.5 kg) | More than 1.0 |
| 20 lb (9.1 kg) | More than 2.0 |
| 30 lb (13.6 kg) | More than 3.0 |
| 50 lb (22.7 kg) | More than 5.0 |
| 70 lb (31.8 kg) | More than 7.1 |
| 90 lb (40.8 kg) | More than 9.1 |
Hidden sources: baking and Christmas food
Dogs rarely eat a measured number of raisins. The usual culprits are foods where dried fruit is mixed in, making the amount hard to count:
- Christmas pudding, mince pies, and fruitcake — packed with raisins, sultanas, and currants. See our Christmas dangers guide.
- Hot cross buns, scones, flapjacks, and cereal bars.
- Trail mix and snack boxes — often combined with chocolate or macadamia nuts.
- Raisin bread and bagels.
If you can't count, assume the worst and call your vet.
Symptoms and timeline
| When | What can happen |
|---|---|
| 0-2 hours | Usually nothing visible. This is the best window for your vet to make your dog vomit. |
| 6-12 hours | Vomiting or diarrhea in most affected dogs. |
| Hours to days after | Lethargy, weakness, loss of appetite, dehydration, drinking more. |
| 24-72 hours | Kidney failure: producing little or no urine. A medical emergency. |
Treatment usually means induced vomiting if it's early, then IV fluids for at least 48 hours with blood tests to watch kidney function. Don't try to make your dog sick at home unless a vet tells you to.
What does an emergency vet visit cost?
Poisoning treatment with IV fluids can mean a hospital stay. See a realistic cost range for your area.
Open the Emergency Vet Cost EstimatorFrequently asked questions
How many grapes or raisins are toxic to a dog?
The Merck Veterinary Manual says more than one grape or raisin per 10 lb (4.5 kg) of body weight may contain enough of the suspected toxin, tartaric acid, to risk kidney injury. That means 2 grapes for a 20 lb dog, or about 7 for a 70 lb dog. But the toxin level varies a lot between fruits, so no amount is known to be safe.
My dog ate one grape. Will they be OK?
Many dogs are, but you can't know in advance which ones won't be, so call your vet. If it's within a couple of hours, your vet may simply make your dog vomit it up — that's quick, cheap, and removes the risk. Waiting to see symptoms is the expensive option: by the time kidney problems show, treatment means days of IV fluids.
Are raisins worse than grapes?
Merck treats them the same — one grape or one raisin per 10 lb. Raisins are easier to eat in large numbers, though: a small box or a slice of fruitcake can hold dozens, so raisin ingestions often add up to more fruit than a few stolen grapes.
Are sultanas and currants dangerous to dogs too?
Yes. Sultanas are dried grapes, and the "currants" used in baking are dried Zante grapes, which Merck lists as a risk. Fresh redcurrants and blackcurrants are a different plant and are not linked to kidney injury.
What are the symptoms of grape poisoning in dogs?
Most affected dogs vomit or have diarrhea within 6-12 hours, then become lethargic, stop eating, and drink more. Kidney failure — producing little or no urine — can develop within 24-72 hours. Don't wait for these signs before calling your vet.
How do vets treat grape or raisin poisoning?
Usually by making the dog vomit if it is early enough, then giving IV fluids for at least 48 hours while monitoring kidney function with blood tests. The earlier treatment starts, the better the outlook and the lower the bill.
Related
Sources
The risk level and timeline on this page come from the Merck Veterinary Manual. Grape toxicity is unpredictable, so treat any ingestion as a reason to call your vet.
- Grape, Raisin, and Tamarind Toxicosis in Dogs — Merck Veterinary Manual. Used for the one-grape-or-raisin-per-4.5-kg risk level, tartaric acid as the proposed toxin, Zante currants vs true currants, the 6-12 hour and 24-72 hour timeline, and treatment (decontamination and at least 48 hours of IV fluids). Checked Oct 1, 2026.
- Food Hazards (pet owner version) — Merck Veterinary Manual. Used for the owner-facing summary of grape and raisin risk. Checked Oct 1, 2026.