We all know that dogs can be masters at swiping things they shouldn’t – maybe it’s something that’s been left on the kitchen counter, or they’ve been hanging around at your feet waiting for something to be dropped on the floor. What happens if they manage to eat grapes?

The simple answer is…go to your vet immediately 

While grapes are a healthy snack for humans, unfortunately grapes are one of those things that dogs cannot eat without the possibility of severe consequences. It is best not to wait around as illness can become more severe if left untreated. 

A dog that has ingested grapes can become very poorly, starting with gastrointestinal signs that may possibly progress to acute renal failure – essentially, their kidneys will begin to shut down. This can ultimately be fatal if left untreated.

Why are grapes poisonous?

For a long time, it’s been unknown exactly what causes this to happen, with many theories presented. New research suggests it could be the presence of tartaric acid in grapes that is the cause of kidney failure.

There is no known toxic dose 

Therefore, in theory, any amount of grapes ingested could lead to severe damage – even just one. The more that are eaten, the more likely they are to cause a problem. It is also likely that the toxic dose will vary between individual dogs. Regardless of how many have been consumed, it is still safest to contact your veterinary practice.

What signs should I look out for?

The following may be associated with grape ingestion. These are likely to develop in 12-24 hours after consumption.

  • Vomiting 
  • Poor appetite 
  • Diarrhoea (with or without blood)
  • Increased drinking and urination
  • Lethargy 
  • Painful abdomen 
  • Dehydration – tacky gums

Severe vomiting tends to be the first presenting sign and also the most common associated with grape poisoning. 

If any less severe signs are missed or ignored, it is possible for dogs to go into shock if severely affected and as the kidneys shut down, may stop producing urine altogether. In this case, emergency veterinary attention is required but prognosis is guarded. Luckily, this very rarely happens!

What can the vets do?

If your dog has eaten grapes recently, the best thing the vet can do is make your dog vomit them back up so that they are not digested. They may also give you some activated charcoal (a lovely messy black liquid!) that further aids in stopping any intestinal absorption. 

If your vets are concerned that there is further damage, they may recommend hospitalisation for intravenous fluid therapy (“a drip”), medication and further monitoring. A blood and urine test can also help to check kidney function and this may need to be regularly monitored. In the most severe cases, dogs can still die despite appropriate veterinary care.

It’s the same for raisins and sultanas

Of course, raisins and sultanas are dried grapes and therefore are still toxic to dogs – in fact, probably more toxic than fresh grapes! Remember that raisins may be found as ingredients in other things, such as cakes and biscuits, so veterinary attention is required if your dog manages to pinch any of these too. Festive periods often tend to be a busy time for vet practices due to dogs pinching Christmas cakes, mince pies and hot cross buns! Treat ingestion of any of these just as seriously as if your dog was to have eaten some chocolate and speak to your vet ASAP.

In conclusion

Grapes and raisins are a big no-no! Keep any grapes, raisins, sultanas, or any products containing these well out of reach of your pet. If you are at all concerned your dog could have eaten any of these, contact your veterinary practice immediately. The sooner your pet is seen and treated, the better the outcome. 

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