Grapes and raisins can be very poisonous to dogs and cause sudden kidney failure. The reason for this is still being investigated, but severe problems have been reported with small amounts. If your dog ingests any amount of grapes or raisins, or products containing them such as Christmas Pudding, speak to a vet immediately.
Dogs are usually quite adventurous about trying new foods and are always interested in what others are eating. This often leads to them eating things that their body is not equipped to digest or process. Grapes and products made from them, such as raisins, sultanas, or Zante currants, are known to cause tummy problems and kidney damage in dogs. Treatment works best if started as soon as possible. Speak to a vet straight away for specific advice.
Are grapes and raisins toxic to dogs?
Research is being done to find out why grapes can be poisonous to dogs.
A recent theory is that the damage is done by tartaric acid, which is also present in tamarinds and is used for baking under the name cream of tartar. Foods containing these should be avoided as well.
Some dogs develop intense vomiting within 24 hours of ingesting grapes or raisins, followed by kidney problems in the next 24-48 hours. Severe cases can be fatal.
The lowest dose of grapes reported to cause toxicity is 11g per kg of body weight, and for raisins is 2.8g per kg. Having said that, we don’t know if a smaller amount could still be dangerous.
Kidneys do not heal when damaged, and it is possible that small amounts will build up over time and cause serious problems.
Grape juice does not appear to cause any problems.
Symptoms of grape or raisin poisoning in dogs
Symptoms of grape or raisin poisoning usually start with vomiting within 6 to 24 hours of ingestion. Signs of kidney failure may take 2-3 days to develop and may cause long-term problems. Other common symptoms are:
- No appetite
- No energy
- Tummy pain
- Bad breath with an ammonia-type smell
- Excessive thirst
- Production of urine may increase initially and then reduce or even stop completely
- Some cases will show weakness, trembling and seizures.
Dogs at higher risk for grape or raisin poisoning
Not all dogs that eat grapes or raisins will become ill, but it is not clear why. This could be due to differences in the content of the grapes themselves.
The tartaric acid content varies depending on grape variety, ripeness and processing.
Another theory says that different dogs are affected differently and only some are susceptible.
Until we know more, it is safer to assume all dogs are at risk of toxicity.
Very small dogs are at much higher risk of eating enough grapes or raisins to develop serious problems.
Diagnosis of grape or raisin poisoning in dogs
Diagnosis of grape or raisin poisoning is usually based on finding out about ingestion and the symptoms. Grapes and raisins may be seen in the vomit or diarrhoea..
After about 24-48 hours, when kidney failure develops, this can be detected on common blood tests.
Veterinary treatment of grape or raisin poisoning in dogs
- The first and most important step in treating intoxications is to stop the poison from getting into the blood and organs. If possible the stomach should be emptied within the first 1-2 hours after having eaten the grapes or raisins, but this may still be useful up to 6 hours later. This can be done with an injection or by pumping the stomach under anaesthesia.
- Activated charcoal may reduce the absorption of toxins from the gut
- If a large amount was ingested or the dog is having symptoms, they will need to be hospitalised and put on a drip. This helps to protect the kidneys and eliminate the toxins from the body.
- If urine production starts to decrease, strong diuretics will be administered to stimulate it
- Vomiting will often need treatment with anti-sickness medication
Home treatment of grape or raisin poisoning in dogs
Until more is known about this problem, most vets consider any ingestion of grapes or raisins potentially life-threatening. Emergency treatment may be needed. Please speak with a vet straight away.
Inducing vomiting at home should be avoided. It is difficult to do and can waste precious time, and there is a significant risk of serious complications like aspiration pneumonia.
Dogs that recover from grape or raisin poisoning may be left with permanent kidney damage and require precautions and supportive treatment for the rest of their life. Please see more information here.
Living with grape and raisin poisoning in dogs
The kidneys do not recover well from injury and most damage will be permanent. In many cases the essential functions will be maintained by uninjured areas working extra hard.
This may leave some dogs more prone to kidney problems in the future or even with chronic kidney disease. If this is the case, diet changes and supportive treatments can be a big help.
Prevention of grape or raisin poisoning
- Make sure everyone in the family knows grapes and raisins can be dangerous to dogs.
- Check labels of baked goods for grapes, raisins, sultanas, Zante currants, tamarinds, cream of tartar, tartaric acid, or potassium bitartrate. Keep any products containing these in a secure, out of reach location and consider putting a dog-danger warning on them.
When to worry
When to worry about grape and raisin poisoning
Seek emergency help from a vet in practice if your dog:
- Has eaten even a small amount of grapes, raisins or any products containing cream of tartar
- Is vomiting after having eaten grapes or raisins
- Is drinking and/or urinating excessively or not passing urine at all
- Showing weakness, stumbling, tremors or seizures
Joii can help if:
- You are not sure if your dog has eaten grapes or raisins
- Your dog is unwell or lethargic
- You need help managing chronic kidney disease