Dog Ate Grapes or Raisins? Grape Toxicity Calculator
Check what your dog has eaten against the vet treatment threshold, from a single grape to a slice of Christmas cake
Last updated: 20 October 2026
Dogs cannot eat grapes, raisins, sultanas or currants. They can cause sudden kidney failure, and no amount is known to be safe. Vets advise treatment if a dog eats more than one grape or raisin per 4.5 kg of body weight.
For example, a 10 kg dog needs treatment after 3 grapes or raisins, and a single mince pie is over the threshold for most dogs. If your dog has eaten any, call your vet now, then use the calculator or the chart by weight while you wait.
Do Not Wait for Symptoms
Kidney damage can take 1 to 3 days to show, and treatment works best when it starts early. Call your vet or emergency vet now. Out of hours you can also call Animal PoisonLine on 01202 509 000 (24 hours, charged). Do not try to make your dog sick at home or give salt water.
This calculator is for information only and is not a substitute for veterinary advice. Some dogs react to very small amounts, so no result here means your dog is safe.
Check What Your Dog Ate
If you are not sure, enter the most it could have been. We assume 4.9 g per grape and 0.5 g per raisin, sultana or currant.
How Many Grapes or Raisins Are Toxic to Dogs? Chart by Weight
The number of grapes or raisins at which the MSD Veterinary Manual advises vet treatment (more than one per 4.5 kg of body weight). Sultanas and currants count the same as raisins.
| Dog’s weight | Vet treatment advised from | About |
|---|---|---|
| 2.5 kg (6 lb) | 1 grape or raisin | 0.5 g of raisinsor 5 g of grapes |
| 5 kg (11 lb) | 2 grapes or raisins | 1 g of raisinsor 10 g of grapes |
| 7.5 kg (17 lb) | 2 grapes or raisins | 1 g of raisinsor 10 g of grapes |
| 10 kg (22 lb) | 3 grapes or raisins | 1.5 g of raisinsor 15 g of grapes |
| 15 kg (33 lb) | 4 grapes or raisins | 2 g of raisinsor 20 g of grapes |
| 20 kg (44 lb) | 5 grapes or raisins | 2.5 g of raisinsor 25 g of grapes |
| 25 kg (55 lb) | 6 grapes or raisins | 3 g of raisinsor 29 g of grapes |
| 30 kg (66 lb) | 7 grapes or raisins | 3.5 g of raisinsor 34 g of grapes |
| 40 kg (88 lb) | 9 grapes or raisins | 4.5 g of raisinsor 44 g of grapes |
| 50 kg (110 lb) | 12 grapes or raisins | 6 g of raisinsor 59 g of grapes |
Below these amounts problems are less likely, not impossible: some dogs have reacted to very small amounts, so call your vet whatever your dog ate. Weights assume 4.9 g per grape and 0.5 g per raisin.
Can One Grape Kill a Dog?
It can happen, but it is rare. Most dogs that eat one grape are not harmed. The problem is that sensitivity varies hugely and cannot be predicted: some dogs have eaten large amounts of raisins without problems, while others have died after a handful, and kidney failure has been reported in an 8.2 kg dog after 4 to 5 grapes.
Because of that, vets work to a deliberately cautious threshold rather than a “safe” dose. For a dog under 4.5 kg, such as a Chihuahua or Yorkshire Terrier, a single grape or raisin is already above it.
You may see 19.6 g per kg quoted online as the toxic dose of grapes. That figure is the median raisin dose from a study of 42 dogs, not a threshold. In the same study, the lowest raisin dose linked to kidney failure was 2.8 g per kg, and another report describes kidney failure from grapes at 4 g per kg. It is not a safe limit to work to.
What Happens if a Dog Eats a Grape? Symptoms and Timeline
First few hours
Often no signs at all. This is the best time to get to the vet, while the fruit may still be in the stomach.
6 to 12 hours
Vomiting (sometimes with bits of grape or raisin in it) and diarrhoea are usually the first signs. Your dog may go off their food.
Within the first day
Lethargy, weakness, tummy pain, trembling and dehydration. Some dogs drink much more than usual.
24 to 72 hours
Kidney failure can develop. Signs include weeing much less or not at all, and collapse. Once the kidneys stop producing urine, the outlook is poor even with intensive treatment.
Not every dog shows early vomiting, so a dog that seems fine the next morning can still be developing kidney problems. That is why vets recommend treatment before symptoms appear.
What to Do if Your Dog Ate Grapes or Raisins
- Call your vet straight away, or an out-of-hours emergency vet. You can also call Animal PoisonLine on 01202 509 000 (24 hours, charged).
- Do not make your dog sick at home. Salt water and other home remedies can be dangerous. Your vet has safe drugs for this.
- Work out what they ate: the type of fruit or food, roughly how much, and when. Take any packaging with you.
- Do not wait for symptoms. Treatment is most effective before the kidneys are affected.
At the vet, treatment usually means making your dog sick to bring the fruit back up if it was eaten recently, possibly activated charcoal, then a drip (intravenous fluids) for at least 48 hours with blood tests to check kidney function. Most dogs treated early recover.
Mince Pies, Christmas Pudding and Other Foods
Dried fruit turns up in lots of foods, especially at Christmas and Easter. Because dried fruit is concentrated, even one item can be well over the threshold. Figures are worked out from UK supermarket ingredient labels.
| Food (one item) | Dried fruit | Over the vet threshold for |
|---|---|---|
| Mince pie | 6.6 gabout 13 raisins’ worth | Dogs up to about 59 kg |
| Christmas pudding (quarter of a 454 g pudding) | 39.6 gabout 79 raisins’ worth | Dogs of any size |
| Christmas or fruit cake (57 g slice) | 13.7 gabout 27 raisins’ worth | Dogs of any size |
| Hot cross bun | 17.3 gabout 35 raisins’ worth | Dogs of any size |
| Malt loaf (fifth of a 260 g loaf) | 7.8 gabout 16 raisins’ worth | Dogs up to about 70 kg |
| Cinnamon and raisin bread | 8.1 gabout 16 raisins’ worth | Dogs up to about 72 kg |
| Garibaldi biscuit | 3.9 gabout 8 raisins’ worth | Dogs up to about 35 kg |
Recipes vary a lot between brands, and deep-filled or homemade versions may contain more fruit. Many mince pie labels only give a percentage for mincemeat, so if you cannot work out the fruit content, call your vet with the packaging. Scones, Eccles cakes, Welsh cakes, panettone, stollen, trail mix and cereals with raisins all count too.
Why Are Grapes Toxic to Dogs?
The leading explanation is tartaric acid, which dogs appear to be unusually sensitive to. The amount in grapes varies with the variety and how ripe they are, which may explain why some dogs eat grapes without problems and others become seriously ill.
Every type is a risk: red, green and seedless grapes, raisins, sultanas and currants, organic and home-grown fruit, and fruit cooked into food. Tamarind and cream of tartar also contain tartaric acid and are treated the same way.
Frequently Asked Questions
Can dogs eat grapes?
No. Grapes, raisins, sultanas and currants can all cause sudden kidney failure in dogs, and there is no amount that is known to be safe. That includes red, green and seedless grapes, organic and home-grown grapes, and dried fruit baked into mince pies, cakes, buns and bread. If your dog has eaten any, call your vet.
Can one grape kill a dog?
It is possible but rare. Most dogs that eat a single grape are not harmed, but some dogs react to very small amounts: kidney failure has been reported in an 8.2 kg dog after 4 to 5 grapes. Because there is no way to tell in advance which dogs are sensitive, the MSD Veterinary Manual advises treatment if a dog eats more than one grape or raisin per 4.5 kg of body weight. For a dog under 4.5 kg, a single grape is above that level.
How many grapes or raisins are toxic to dogs?
There is no known safe or toxic amount, because dogs react very differently. The MSD Veterinary Manual advises vet treatment above one grape or raisin per 4.5 kg of body weight, so 3 or more for a 10 kg dog. The lowest raisin dose linked to kidney failure in a study of 42 dogs was 2.8 g per kg. You may see 19.6 g per kg quoted as a threshold for grapes: that was the median raisin dose in the same study, not a safe limit, and kidney failure has been reported from grapes at 4 g per kg.
How long after eating grapes will a dog get sick?
Vomiting or diarrhoea often starts within 6 to 12 hours. Kidney failure can develop over the next 24 to 72 hours, and some dogs show no early signs at all. That is why vets recommend treatment straight away, before symptoms appear, rather than waiting to see.
My dog ate one grape and seems fine. What should I do?
Call your vet or Animal PoisonLine for advice anyway, and tell them your dog's weight and roughly when it happened. Seeming fine does not rule out a problem, because kidney damage can take 1 to 3 days to show. For a dog under 4.5 kg, one grape is above the level at which the MSD Veterinary Manual advises treatment.
Can dogs eat sultanas or currants?
No. Sultanas and currants are dried grapes, just like raisins, and are treated the same way by vets. Because they are dried, they are more concentrated than fresh grapes, so a small handful can be a large dose for a small dog.
What should I do if my dog ate grapes or raisins?
Call your vet straight away, or Animal PoisonLine on 01202 509 000 (24 hours, charged). Do not try to make your dog sick at home or give salt water. Note what they ate, roughly how much and when, and take any packaging with you. Your vet may make your dog sick to bring the fruit back up, give activated charcoal, and put them on a drip for at least 48 hours with blood tests to check their kidneys.
Can dogs survive grape or raisin poisoning?
Yes, most do, especially when treated early. A 2026 study of more than 31,000 cases seen at 64 UK emergency vet clinics found that fewer than 1 in 100 dogs died. The outlook is much worse once the kidneys stop producing urine, so getting treatment before symptoms appear matters.