While some human food is safe for canines, if dogs eat grapes or raisins, it can cause many side effects and pose a real threat to them. If you are someone who regularly keeps grapes or raisins in the house, you must understand the dangers if your dog snatches a grape from your plate.
Can Dogs Eat Grapes?
The short answer to this question is, absolutely no. There is a substance in the flesh of grapes that has extremely high toxicity for dogs, and it can negatively impact internal systems, particularly the kidneys. Although many other fruits are perfectly safe for dogs to eat in moderation, grapes and raisins must be strictly avoided. If you have a curious pooch who likes to grab food from your plate, never leave grapes or raisins unattended. The results can be disastrous, if not downright deadly. 
Do Grapes Kill Dogs?
In certain cases, the ingestion of grapes or raisins can be fatal to your dog. The deadly nature of this fruit (in fresh or dried form) comes from a toxin in the flesh of the fruit, although researchers are yet to determine what the toxic component precisely is. The effects will happen very quickly, often within an hour or two of eating these fruits.
Grape and raisin poisoning does the most damage to the kidneys, and can even cause acute renal failure, which can often lead to death. Interestingly, not all dogs will experience severe side effects when grapes are consumed, while other dogs appear to be extremely sensitive to the toxic components. Given this uncertainty, it is best to eliminate the chance of your dog eating grapes or raisins in any way. 
Causes of Grape Poisoning
The cause of this poisoning, as mentioned above, is an as-yet-unspecified toxic component in the flesh of the grapes. This means that all types of grape products and derivatives can be harmful to your dog’s renal health, and should be avoided at all costs. Peeled and seedless grapes are the same as normal ones, and should also be avoided.
Symptoms of Grape Poisoning
The main effects when dogs eat grapes include nausea, vomiting, loss of appetite, dehydration, bad breath, anuria (lack of urination), tremors, seizures, abdominal pain, oliguria (very low level of urination), oral ulcers, fatigue, lethargy, and even comas, in some cases. Grape or raisin poisoning is deadly and can cause the kidneys to stop functioning altogether. 
Treatments for Grape Poisoning
If dogs eat grapes, action must be quickly taken to prevent the most serious or fatal side effects. First and foremost, if you see your dog eating grapes or raisins, you should immediately attempt to induce vomiting. The sooner your dog vomits up the fruits, the less time the toxins will have to get digested.
In some cases, the dog will respond very rapidly to eating grapes or raisins and will vomit on its own. Once this happens, there is no need to induce further vomiting, but you should immediately contact your veterinarian for any emergency treatment. 
If you need to induce vomiting at home, use 1 milliliter of 3% hydrogen peroxide per pound of your dog’s weight. In a small syringe or turkey baster, squirt the hydrogen peroxide into the back of your dog’s throat. This should induce vomiting within 15 minutes. If it doesn’t, repeat the process. If that still doesn’t work, get your dog to a veterinarian as soon as possible.