Last updated: June 19, 2026
Dog Raisin Toxicity Calculator
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Quick Answer
The Dog Raisin Toxicity Calculator estimates the risk if a dog ate grapes or raisins, using dose (g/kg) = grams of fruit ÷ dog weight in kg, then comparing it to the veterinary reference toxic dose. Reference toxic doses are about 19.6 g/kg for fresh grapes and 2.8 g/kg for dried fruit (raisins, sultanas, currants), which are roughly 7 times more concentrated. Risk bands are: under 25% of the reference dose Low, 25–100% Moderate, 100–200% High, and 200%+ Severe (no proven safe dose). The likely toxin is tartaric acid, and the main danger is sudden acute kidney injury, which can appear 24–72 hours after ingestion. Toxicity is idiosyncratic with no proven safe dose, so owners should contact a vet or pet poison helpline immediately after any grape or raisin ingestion rather than waiting for symptoms.
To estimate raisin toxicity, divide the grams of fruit your dog ate by its weight in kilograms to get the dose, then compare it with the reference toxic dose — about 19.6 grams per kilogram for grapes and just 2.8 for raisins. Because toxicity is unpredictable and there is no proven safe dose, call your vet immediately if your dog ate any grapes or raisins.
Key Takeaways
- Dose (g/kg) = grams of fruit ÷ dog weight in kg; risk = dose ÷ reference toxic dose
- Reference toxic dose: fresh grapes ~19.6 g/kg, raisins/sultanas/currants ~2.8 g/kg
- Dried fruit is ~7× more concentrated than grapes — raisins are far more dangerous gram-for-gram
- The toxin is likely tartaric acid; the danger is sudden acute kidney injury
- Toxicity is idiosyncratic — there is NO proven safe dose, even a 'Low' result needs a vet call
- If your dog ate any grapes or raisins, contact a vet or pet poison helpline immediately
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Formula
Dose (g/kg) = Amount ÷ Dog Weight · % of Toxic Dose = (Dose ÷ Reference Toxic Dose) × 100
Where:
- D=Dose ingested(g/kg)
- m_{fruit}=Amount of grapes or raisins eaten(g)
- W_{dog}=Dog weight(kg)
- D_{ref}=Reference toxic dose (by fruit type)(g/kg)
Worked Examples
10 kg dog eats 30 g of raisins
A medium dog gets into a small handful of raisins.
- 1Dose = 30 g ÷ 10 kg = 3 g/kg
- 2Reference toxic dose for raisins ≈ 2.8 g/kg
- 3% of toxic dose = (3 ÷ 2.8) × 100 ≈ 107%
- 4107% → High risk (at/above the reference toxic dose)
- 5Treat as an emergency — call your vet immediately
20 kg dog eats 50 g of grapes
A larger dog eats a few fresh grapes off the floor.
- 1Dose = 50 g ÷ 20 kg = 2.5 g/kg
- 2Reference toxic dose for grapes ≈ 19.6 g/kg
- 3% of toxic dose = (2.5 ÷ 19.6) × 100 ≈ 13%
- 413% → Low (below the reference dose)
- 5Still call your vet — toxicity is unpredictable and there is no proven safe dose
5 kg dog eats 20 g of sultanas
A small dog steals dried fruit from a baking tray — a true emergency.
- 1Dose = 20 g ÷ 5 kg = 4 g/kg
- 2Reference toxic dose for dried fruit ≈ 2.8 g/kg
- 3% of toxic dose = (4 ÷ 2.8) × 100 ≈ 143%
- 4143% → High risk
- 5Go to an emergency vet now — small dogs reach toxic doses very fast
30 kg dog eats 500 g of grapes
A large dog raids a whole bunch of grapes.
- 1Dose = 500 g ÷ 30 kg = 16.67 g/kg
- 2Reference toxic dose for grapes ≈ 19.6 g/kg
- 3% of toxic dose = (16.67 ÷ 19.6) × 100 ≈ 85%
- 485% → Moderate (approaching the reference toxic dose)
- 5Contact your vet or a pet poison helpline immediately
Introduction
The Dog Raisin Toxicity Calculator estimates how dangerous it is if your dog ate grapes, raisins, sultanas or currants, and tells you how worried to be. Grape and raisin poisoning can cause sudden acute kidney injury (AKI) in dogs — and the risk depends on your dog's weight, the type of fruit (dried fruit is roughly 7× more concentrated than fresh grapes), and the amount eaten. This tool computes the dose in grams per kilogram of body weight, compares it with the veterinary reference toxic dose, and tells you what to do next. Important: grape and raisin toxicity is unpredictable — there is no proven safe dose. This is a guide, not a diagnosis. If your dog ate any grapes or raisins, call your vet or a pet poison helpline immediately. For other canine tools see our Dog Chocolate Toxicity Calculator, Dog Onion Toxicity Calculator, and Dog Age Calculator.
⚠️ If Your Dog Just Ate Grapes or Raisins
Don't wait for symptoms — kidney injury can take 24–72 hours to show, and by then treatment is harder. Act now:
Estimate the type and amount as accurately as you can (count grapes/raisins or check the packaging weight)
Call your vet or a pet poison helpline now — ASPCA Animal Poison Control (USA): (888) 426-4435; Pet Poison Helpline: (855) 764-7661; in the UK, the Animal PoisonLine: 01202 509000
Do not induce vomiting unless a vet tells you to — doing it wrong can cause aspiration
Note the time of ingestion — it determines whether decontamination is still useful
Bring the packaging so your vet can confirm the amount and fruit type
Because toxicity is idiosyncratic and there is no antidote, vets often recommend treating ANY grape or raisin ingestion — inducing vomiting and starting IV fluids — rather than risking kidney failure. The sooner you act, the better the outcome.
Why Grapes and Raisins Are Toxic to Dogs
For years the toxic agent was a mystery. Research published in 2021 points to tartaric acid and its salt potassium bitartrate — compounds dogs appear unusually sensitive to — as the likely cause of grape and raisin poisoning.
Tartaric acid content varies between grape varieties and with ripeness, which helps explain why some dogs react and others don't
Dogs lack an efficient pathway to handle tartaric acid, leading to kidney tubule damage
Drying concentrates the fruit: raisins, sultanas and currants carry far more tartaric acid per gram than fresh grapes
The result is acute kidney injury — the kidneys can suddenly stop filtering waste
Sensitivity is idiosyncratic: a dose that harms one dog may not affect another, so no amount is proven safe
It's not just whole grapes and raisins — foods made with them count too. Trail mix, fruitcake, hot cross buns, raisin bread, oatmeal-raisin cookies and grape juice have all caused poisoning.
Reference Toxic Dose by Fruit Type
These are the lowest documented toxic doses used by veterinary toxicologists as practical thresholds. Note how much smaller the dried-fruit threshold is — that's why raisins are so dangerous.
| Fruit type | Reference toxic dose | Example for a 10 kg dog |
|---|---|---|
| Fresh grapes | ≈ 19.6 g/kg (~0.7 oz/kg) | ~196 g (~40 grapes) reaches the reference dose |
| Raisins (dried) | ≈ 2.8 g/kg (~0.1 oz/kg) | ~28 g (~55 raisins) reaches the reference dose |
| Sultanas / golden raisins | ≈ 2.8 g/kg | ~28 g reaches the reference dose |
| Dried currants | ≈ 2.8 g/kg | ~28 g reaches the reference dose |
These are reference points, not safe limits. Dogs have developed kidney failure after eating far less, and some tolerate more. Always treat ingestion as potentially serious.
Risk Levels (Percentage of the Reference Toxic Dose)
This calculator compares the dose your dog ate with the reference toxic dose for that fruit, then assigns a risk band.
| % of reference dose | Risk level | What it means |
|---|---|---|
| < 25 % | Low | Below the reference dose — but still call a vet; toxicity is unpredictable |
| 25–100 % | Moderate | Approaching the reference toxic dose — contact a vet immediately |
| 100–200 % | High | At or above the reference toxic dose — veterinary emergency |
| ≥ 200 % | Severe | Well above the reference dose — high risk of acute kidney injury |
Even a 'Low' result is not a green light. Because some dogs react to tiny amounts, veterinary advice is to contact a professional after any grape or raisin ingestion.
Symptoms of Grape and Raisin Poisoning
Signs often start within 6–24 hours, but kidney damage may not be obvious for 24–72 hours — which is why early action matters so much.
- **Early (within hours):
** vomiting (often containing fruit pieces), diarrhoea, loss of appetite, lethargy
- **Within a day:
** weakness, drooling, abdominal pain, dehydration
- **Kidney signs (24–72 h):
** increased then decreased urination, increased thirst
- **Severe / late:
** little or no urine production (anuria), tremors, bad breath with an ammonia smell
- **Critical:
** complete kidney failure, which can be fatal without treatment
A drop in urine output is an ominous sign — once the kidneys stop producing urine, the prognosis is poor. This is why vets monitor kidney values and urine output closely after ingestion.
How Vets Treat Grape and Raisin Toxicity
There's no antidote, so treatment focuses on stopping absorption and protecting the kidneys.
Induced vomiting if ingestion was recent (usually within ~2 hours)
Activated charcoal to bind any remaining toxin in the gut
Aggressive IV fluids for 48–72 hours to support and flush the kidneys
Blood tests to monitor kidney values (BUN, creatinine, phosphorus) and electrolytes
Urine output monitoring — sometimes with a urinary catheter
Medications to support urine production and control vomiting; dialysis in severe failure
Preventing Accidental Ingestion
Most poisonings are accidents in the home. A few habits dramatically cut the risk:
Store grapes, raisins and trail mix in closed cupboards, not on counters or low shelves
Be extra careful with baked goods — fruitcake, hot cross buns and raisin bread are common culprits
Tell children and guests never to share grapes or raisins with the dog as a treat
Watch dogs closely around vineyards, picnics and compost bins
Use dog-safe treats instead — see our Dog Nutrition Calculator for healthy options
Keep a pet poison helpline number saved in your phone and your vet's emergency line on the fridge — minutes matter with kidney toxins.
Glossary
Quick definitions for the terms used in this calculator:
| Term | Definition |
|---|---|
| Tartaric acid | The compound now believed to cause grape and raisin toxicity in dogs. |
| Acute kidney injury (AKI) | A sudden loss of kidney function — the main danger of grape/raisin poisoning. |
| Idiosyncratic toxicity | Toxicity that varies unpredictably between individuals, with no reliable safe dose. |
| g/kg | Grams of fruit per kilogram of body weight — the dose that drives risk. |
| Reference toxic dose | The lowest documented toxic dose, used as a practical risk threshold. |
| Decontamination | Removing toxin from the body — induced vomiting plus activated charcoal. |
| Anuria | Producing little or no urine — a sign of severe kidney failure. |
Quick Reference Card
Dog Raisin & Grape Toxicity — Quick Reference
Quick reference • Dog Raisin Toxicity Calculator
Dose (g/kg) = grams ÷ weight(kg) · % toxic = dose ÷ ref dose × 100 · ref: grapes 19.6 · raisins/sultanas/currants 2.8 g/kgValid range: Risk: <25% Low · 25–100% Moderate · 100–200% High · ≥200% Severe (no proven safe dose)
Common Values
⚠ Watch Out
- •There is no proven safe dose — even a 'Low' result needs a vet call
- •Don't wait for symptoms — kidney damage can take 24–72 hours to show
- •Don't induce vomiting unless a professional instructs you to
- •Raisins, sultanas and currants are far more dangerous than fresh grapes
Pro Tips
- →Save a poison-helpline number in your phone before you ever need it
- →Keep packaging to help the vet estimate the amount and fruit type
- →Remember hidden sources: trail mix, fruitcake, raisin bread, grape juice
- →A drop in urine output is an emergency sign — seek care immediately
FAQs
How many grapes or raisins are toxic to a dog?
There is no proven safe number — toxicity is unpredictable. As a practical reference, the lowest documented toxic doses are about 19.6 g/kg for fresh grapes and just 2.8 g/kg for raisins. For a 10 kg dog that's roughly 40 grapes or about 55 raisins (~28 g), but dogs have been poisoned by far less. Use the calculator with your dog's actual weight, and call your vet after any ingestion.
My dog ate a raisin — should I worry?
Possibly. Because some dogs are sensitive to tiny amounts, vets generally recommend contacting a professional even after a single raisin, especially for small dogs. Estimate how many were eaten, note the time, and call your vet or a pet poison helpline (ASPCA APCC: 888-426-4435; Pet Poison Helpline: 855-764-7661). Don't wait to see if symptoms develop.
Are raisins more dangerous than grapes?
Yes, gram for gram. Drying removes the water and concentrates the toxin, so raisins, sultanas and currants are roughly 7 times more potent than fresh grapes. That's why the reference toxic dose for raisins (~2.8 g/kg) is far lower than for grapes (~19.6 g/kg) — a small handful of raisins can be as dangerous as a large bunch of grapes.
How long after eating grapes will a dog show symptoms?
Early signs like vomiting, lethargy and loss of appetite often appear within 6–24 hours. However, kidney damage may not be obvious for 24–72 hours, and a drop in urine output is a late, serious sign. Because of this delay, you should act before symptoms start rather than waiting to see what happens.
What makes grapes and raisins toxic to dogs?
Research published in 2021 points to tartaric acid and its salt potassium bitartrate as the likely cause. Dogs appear unusually sensitive to tartaric acid, which can damage the kidney tubules and lead to acute kidney injury. Tartaric acid content varies between grape varieties and ripeness, which helps explain why toxicity is so unpredictable.
Can other grape products poison dogs?
Yes. It's not just whole grapes and raisins — anything made with them can be toxic, including trail mix, fruitcake, hot cross buns, raisin bread, oatmeal-raisin cookies, and grape juice. Currants and sultanas carry the same risk as raisins. Wine is a double hazard because of both grapes and alcohol.
How accurate is this calculator?
It uses the standard veterinary reference toxic doses and a clear dose-per-kilogram comparison, so it gives a useful sense of risk. But it cannot account for everything: toxicity is idiosyncratic, tartaric acid content varies by grape variety, and an individual dog's kidney health matters. Treat it as a guide and always confirm with a vet — a 'Low' result still warrants a phone call.