Can Dogs Eat Grapes?

You’ve probably heard that grapes are one of the most toxic fruits for dogs, but it’s still a little unclear what doses are toxic and what makes them so harmful to dogs. Needless to say, dogs can’t eat grapes—and they shouldn’t!

All types of grapes are dangerous for dogs (both red and white grapes), and even dried grapes—raisins—are toxic to them. That’s why I insisted on writing about toxic Christmas foods for dogs, as we often have lots of sweets with grapes, including traditional Christmas fruit cake and Panettone.

Now, grapes are toxic to dogs, but studies are limited. There was a huge breakthrough by scientists from the ASPCA about what makes grapes toxic to dogs, but even they say it’s not 100% definitive. Let’s look at the key findings!

What makes grapes toxic to dogs?

For years, we’ve known that grapes are toxic to dogs because they cause kidney failure, but no one knew exactly why. Then, the ASPCA published a study in the Journal of Veterinary Emergency and Critical Care, where they discovered that dogs experienced kidney damage when they came into contact with the cream of tartar, tartaric acid, or tamarinds.

What is tartaric acid?

Tartaric acid is a byproduct of grapes and wine. It’s also found in other fruits, but it’s most common in grapes. Tartaric acid has a salt called potassium bitartrate, which we know as cream of tartar. We use cream of tartar in baking, like when making cookies and desserts, because it helps create the perfect meringue!

Humans can process cream of tartar just fine, but dogs can’t.

The ASPCA study found that dogs are sensitive to the cream of tartar and can experience acute kidney injuries after exposure.

After eating grapes, dogs went through problems like vomiting, diarrhea, and kidney failure.

What did the ASPCA study reveal?

I found the study paper on ASPCA’s Facebook page (check the link), but they published their findings in the Journal of Veterinary Emergency and Critical Care based on real-life reports.

They found that some dogs that accidentally ate homemade playdough showed the same symptoms as seen with grapes and raisins. This was a huge discovery as they linked that dogs are actually sensitive to tartaric acid, which is found in cream of tartar, grapes, and raisins. Here’s what we know about grape toxicity and dogs.

It’s not clear how many grapes are toxic to dogs

We still don’t know the exact toxic doses for grapes, as we do for chocolate. A dog’s size is a huge factor, but so is the type of grape and whether it’s a fresh grape or a raisin.

According to the ASPCA’s findings, a dose of 19.6 mg of tartaric acid per kg of body weight from raisins caused serious and severe kidney damage in some dogs.

Additionally, some dogs experienced these health problems after eating only small amounts of grapes.

However, the exact amount of raisins that can cause a toxic dose remains a mystery. I did some digging and found a study about tartaric acid, which provided information about how many milligrams of tartaric acid are in one raisin.

Based on my calculations, it looks like a single raisin contains about 7.29 mg of tartaric acid. This is just an approximate calculation, so please take it with a grain of salt!

Now, back to this:

“In the ASPCA’s findings, a dose of 19.6 mg of tartaric acid per kg of body weight from raisins caused serious and severe kidney damage in some dogs.”

This means that the amount of raisins toxic to dogs looks something like this:

These are approximate amounts, as raisin weights and tartaric acid content can vary depending on the type of grape, how the raisins were processed, and other factors.

How tartaric acid affects dogs

Tartaric acid is toxic to dogs because it damages their kidneys, making them unable to filter waste and maintain normal fluid levels in the body. This leads to kidney failure and increases creatinine levels in the blood.

Dogs don’t have the mechanisms in their bodies to safely break down and digest tartaric acid without experiencing these health issues.

Raisins are even more toxic to dogs than grapes

So far, I’ve explained that dogs shouldn’t eat grapes, raisins, or cream of tartar, but it’s important to remember that if your dog eats a single grape or even a couple of fresh grapes, it’s highly unlikely that an average-sized dog will experience any issues.

However, raisins are more dangerous to dogs than grapes because they are more concentrated.

Raisins contain higher amounts of tartaric acid per gram than fresh grapes. Grapes also have more water and fiber, which makes their tartaric acid content less concentrated.

Dogs can’t eat cream of tartar

In addition to raisins, dogs shouldn’t eat foods that contain cream of tartar. This includes all baked goods or anything made with cream of tartar. Even small amounts of baked products that include cream of tartar can be harmful to dogs.

Here are some common foods that often include raisins and should never, ever be given to dogs:

• Christmas fruit cakes: These are loaded with raisins.
• Panettone: Another festive treat packed with raisins.
• Oatmeal with raisins: Oatmeal with raisins is a healthy breakfast for us, but dangerous for dogs.
• Granola: It often contains raisins and some nuts that are not dog-friendly! So, overall, granola is not safe for dogs.
• Pancakes with raisins: Sometimes when we make pancakes we add raisins to the batter. This is not a safe combination for dogs!
• Cakes, including cheesecake: Many cakes have raisins, so be extra careful about what you leave on the table, especially if your dog has a sweet tooth.

While we still don’t know the exact toxic dose, we need to be cautious about the foods we share with dogs and ensure they don’t eat anything containing grapes, raisins, or cream of tartar!

Love, life, and fur forever!

FAQs

Can dogs eat seedless grapes?

No, dogs can’t eat seedless grapes because they also contain tartaric acid, which is toxic to dogs. It doesn’t matter whether the grapes are seedless or not, red or white—they all contain tartaric acid that makes them sick and damages their kidneys.

Can dogs eat grape leaves?

I don’t think your dog will ever eat grape leaves, but if they do, don’t worry. If you’re cooking with grape leaves (like making minced meat rolls) and your dog eats some (or steals some), there’s no need to panic. Grape leaves are not toxic to dogs. However, grape vines and grapes themselves are toxic, so it’s better to avoid anything associated with grapes!

Can dogs eat frozen grapes?

No, dogs should not eat frozen grapes. Grapes, whether fresh, frozen, or dried (like raisins), are toxic and dangerous to dogs as they cause kidney failure.