What’s Up with Grapes?

Grape toxicity in dogs seems sort of random, doesn’t it? Some dogs get just a little bit of stomach upset and diarrhea from slurping up amounts of grapes that would make a human queasy, and some dogs need extensive care to manage the kidney damage caused from eating just a raisin or two. Many people claim to have fed their dogs the occasional grape for years without issue. What is going on there? And this being the case, how can you possibly know what to do if your dog eats a grape?

What Makes a Grape Toxic?

Grapes, raisins, sultanas, and currants can all cause GI upset and kidney injury in dogs, but for a very long time, nobody was sure why. In March of 2021, veterinary toxicologists from the ASPCA Poison Control Center announced their discovery that the tartaric acid found in these foods is what causes them to be toxic to dogs. Tartaric acid can also be found in tamarinds and cream of tartar, which are also unsafe for dogs to ingest. However, there is not a consistent amount of tartaric acid between grapes. The amount within a certain grape differs depending on the type, where it was grown, what time of year it was grown, and other factors. For this reason, there is no way to know for sure exactly how much toxin a dog has consumed when they eat one (or several).

Then What Happens if My Dog Eats Grapes?

Now we know why it’s hard to determine exactly what will happen to a dog who has eaten some type of grape. But what does that mean for you and your pet? How can we know what to do if your dog steals some grapes or a raisin cookie?

• Gather information.
  • First, try to determine how many grapes your dog ate, what type they were, and how long ago your dog ate them. It’s helpful to have as much information as possible.
• Call your vet and let them know what happened. A vet can let you know if it is recommended to come in for a visit, monitor the situation, or head to the emergency room. If a veterinarian isn’t available, call ASPCA Poison Control at (888) 426-4435. Their staff and board certified toxicologists are available 24 hours a day.
• Seek care sooner rather than later. Treatment will be much easier for your dog (and you) the sooner it’s begun. If detected early enough, your vet may be able to keep grapes from entering your dog’s system by inducing vomiting. If it is too late for that, intravenous drip fluids can help minimize the damage done to the kidneys and keep your dog from feeling sick.

Signs and symptoms

If your dog displays these symptoms after eating grapes, even in a small amount, please seek care:

• Vomiting and diarrhea
• Lack of interest in food
• Increase in thirst
• Excessive urination or not urinating at all

If you notice any of the following symptoms, please take your pet to an emergency hospital right away:

• Lethargy
• Labored breathing
• Seizure activity

Even if your dog has eaten grapes before and seemed to have a great time of it, there is no way to know just how toxic any given grape will be. If your dog just can’t get through without stealing some raisin loaf, let a veterinary professional know as soon as possible. Quick action can make a big difference in preventing serious illness. When in doubt, it’s always better to call your vet and be safe rather than sorry.