Can Dogs Eat Grapes?
Dogs must not eat onions and they definitely must not eat grapes. Many dogs die of acute renal (kidney) failure within a few hours or days of eating grapes or any of the grape family. Consuming grapes is an absolute emergency! And it only takes a tiny amount (approx. 10 mg per kg body weight) to kill a susceptible dog.
Eating grapes causes kidney failure in dogs
No one yet knows what causes the acute renal failure, nor why some dogs can eat grapes with no ill effects and some die with the first sniff of grape.
What Are The Symptoms When A Dog Eats Grapes?
These vary, but may include vomiting within the first 2 hours (this is a good thing, ridding the dog of whatever toxin it has swallowed). This may be followed by diarrhoea, lethargy and great thirst (polydipsia).
So make sure there is always fresh chemical free water available and accessible at all times. The signs of the acute renal failure stage may appear within the first 24 hours, or sometimes after a few days. This is a very serious and life-threatening situation.
Extreme lethargy, inappetence, uraemic breath (smells fetid, fishy, like urine or ammonia) and collapse are often added to the initial symptoms. The blood picture shows the usual markers of renal failure, with increased BUN, creatine, calcium and phosphorus.
Once the renal tubules start to disintegrate, the dog can no longer produce urine and is very unlikely to recover. A Christmas advert produced by a well known UK store was hastily removed when this fact was pointed out to them. The lovely Christmas scene of a family sharing bits of cake and mince pies with their dog could have led to countless grape poisoning deaths that Christmas.
What Counts As A Grape?
The grape family includes fresh red, black or white (actually green) grapes, with and without seeds and their pulp (from the juice and wine industry) and dried products including raisins, sultanas and currants.
Remember grapes include Christmas puddings, mince pies, eccles cakes and fruit cakes.
Interestingly, the seeds and the antioxidant rich supplement grape seed extract (GSE) are fine (not to be confused with grapefruit seed extract, also called GSE). The proanthocyanidins in GSE are potent antioxidants and found in the seeds and skins of many berries, including grapes, cranberries, blueberries, aronia, hawthorn, rosehip, sea buckthorn, all the Prunus family, as well as the bark of Cinnamon and Pinus pinaster (was P maritima), the latter being known as pycnogenol.
What To Do If Your Dog Eats Grapes
The treatment is the same as for all ingested toxins (for more detail, see my article on dogs and onions).
- Open the mouth and remove every scrap from the mouth.
- You might even manage to induce vomiting if you put your fingers far enough down your dog’s throat. That would be great.
- Remove the food to prevent further ingestion.
- Give activated charcoal or medicinal clay by mouth to adsorb the toxins.
- Give water by mouth to dilute the toxins and keep the dog hydrated.
- Phone the vet and take your dog there as an absolute emergency.
At the veterinary surgery they will induce vomiting if the ingestion of the grapes was recent (within 2 hours). They will put your dog on intravenous fluids and use appropriate medications depending on the clinical state of your dog. The blood tests will show whether the kidneys have been affected yet.
The intravenous fluids will keep the kidneys working and dilute the toxins in the hopes that they will then be less likely to destroy the renal tubules and thus the kidneys. If your dog has stopped producing urine, it shows the kidneys have stopped working. The prognosis is very poor in this case, as the kidneys may be irreversibly damaged.
What is it about grapes that is so toxic? No-one knows for sure what causes this toxicity. Various hypotheses have been suggested, including mycotoxins (moulds) on the skin, metabolic disruption or individual reaction (idiosyncratic) but nothing has been proved yet. So, as with everything, prevention is better than cure. Make sure your dog stays away from grapes.