Grapes, Nuts, and Your Dog’s Health: Foods Fido Should Avoid

“Magoo was a big, playful labrador retriever who often got into difficult situations …”

So begins a story in the latest ASPCA report about foods that can be toxic to dogs. Turns out Magoo crawled into the pantry and snagged about a pound of raisins. He ate it all, of course.

The ASPCA never mentions Magoo’s fate. But they do tell us that as little as a handful of raisins can affect a dog’s health and has been fatal for some. The same goes for the grape.

Who knows?

Growing up, I thought of our family’s dogs as “the first cycle of the dishwasher.” They were fine waiting their turn for what we put on our plates, and we weren’t too concerned about offering “food to the people.” It never crossed our minds that our dogs’ health could be affected by a few measly table scraps. What was safe for us, we thought, was safe for our pets.

What’s more, every time I ate grapes, I liked to give one or two to our German Shepherd “Tiffany”. Grapes always came out of her mouth when she tried to bite into them and Tiffany, always the good sportswoman, refused to give up until she crushed each one into submission. Guaranteed at least 60 seconds of harmless fun.

Tiffany also liked to chew gum (she chewed it, wrapped and all, but she didn’t swallow it!). We had the sugar-free type, which is often sweetened these days with xylitol.

Little did I know that he could have been poisoning our family’s pet! (More on xylitol below).

Why are grapes harmful?

When it comes to grapes and raisins, no one is sure why they are harmful. It has been confirmed that even grapes grown without fertilizers or pesticides can be toxic to dogs. But not for all dogs, and not for all occasions. It is also not known whether small amounts ingested over a long period could have a cumulative effect.

What we do know is that the end result in almost all reported cases of grape or raisin toxicity is acute kidney failure. (The term “acute” means the condition is severe and comes on quickly.) The dog is ultimately unable to produce urine, which means it cannot filter toxins from its systems, a process essential to life.

During the twelve-month period in which the effects of grapes were studied, the ASPCA Animal Poison Control Center handled 140 cases involving one or more dogs. More than a third of the dogs developed symptoms ranging from vomiting to kidney failure, and seven dogs died. The ASPCA based its study on reported cases, so naturally there may be cases where a dog’s health is not affected by consuming grapes. But until they know all the facts The Society advises against feeding grapes or raisins in any quantity to pets.

An ounce of prevention

Then your dog has just scored a big box of raisins. What can a pet owner do?

The first line of defense, if the grapes or raisins were recently eaten, is to induce vomiting and administer activated charcoal (absorbs toxins from the gastrointestinal tract). Vomiting is also the first sign that your dog is in trouble, so go straight to activated charcoal if vomiting has already occurred. (In a pinch, you can make your own activated charcoal by charring a toast until it turns black and easily crumbles.) Then call your vet right away.

Can’t get in touch with the vet? Call ASPCA Poison Control: 888-426-4435

The vet will keep your dog on IV fluids for at least 48 hours and will monitor blood chemistry on a daily basis. A normal blood test after 3 days usually means your dog is healthy.

Keeping a watchful eye, of course, is the best way to keep your pet from getting into trouble. Like children, dogs (and other pets) have a knack for mischief when we are not looking.

It’s not just the grapes …

There are other foods your dog should stay away from, and some of them may surprise him.

Here are some other foods that can endanger a dog’s health:


Who can resist chocolate? As if you didn’t have, your dog.

Chocolate is made from cocoa beans, and cocoa beans contain a chemical called theobromine, which is toxic to dogs. Different types of chocolate have different effects on the health of dogs. Dark chocolate has the largest theobromine, coming in at a whopping 450mg (compared to 1mg for white chocolate). So on Valentine’s Day, you’ll be being nice to your best friend if you eat all the chocolates yourself!

Cocoa mulch

Cocoa bean shells are a by-product of chocolate production (which is how mulch became the “food” category) and are popular as a garden mulch. Homeowners like the attractive color and aroma, and the fact that the mulch breaks down into an organic fertilizer. However, some dogs like to eat it and it contains theobromine.

Fatty foods

Fatty foods are difficult for a dog to digest and can overload the pancreas and lead to pancreatitis. This can endanger your dog’s health and is potentially fatal.


Macadamia nuts should be avoided. In fact, most nuts are not good for the health of dogs, as their high phosphorus content is said to lead to bladder stones.


Mulch is not food, but there is one type that is tempting enough for dogs to eat. Some dogs are attracted to cocoa mulch and eat it in varying amounts. The shells of coca beans can contain 0.2% to 3% theobromine (the toxin) compared to 1-4% of raw beans.


Onions, especially raw onions, have been shown to trigger hemolytic anemia in dogs. (Stephen J Ettinger, DVM and Edward C. Fieldman, DVM book: Textbook of Veterinary Internal Medicine vol. 2 pg 1884.) Stay away from onion powder as well.


Potato poisonings among people and dogs are rare, but have occurred. The toxin, solanine, is poorly absorbed and is only found in green shoots (these are found on tubers exposed to sunlight) and on the skin of green potatoes. This explains why incidents rarely occur. Keep in mind that cooked mashed potatoes is fine for a dog’s health, it’s actually quite nutritious and digestible.

Artificial sweeteners

Xylitol is used as a sweetener in many products, especially sugar-free candies and gum. Ingesting large amounts of xylitol-sweetened products can cause a sudden drop in blood sugar in dogs, resulting in depression, loss of coordination, and seizures. According to Dr. Eric K. Dunayer, Consultant Veterinarian in Clinical Toxicology at the Poison Control Center, “These signs can develop quite quickly, sometimes less than 30 minutes after ingestion of the product,” states Dr. Dunayer, “… therefore, it is important that pet owners seek veterinary treatment immediately.”


Currently, turkey skin is believed to cause acute pancreatis in dogs, in part due to its high fat content.

Other foods listed by the ASPCA as harmful:

Alcoholic drinks

Lawyer (the only “fatty” member of the vegetable family)

Coffee (all forms of coffee)

Moldy or spoiled food


Yeast dough


The bottom line

Thanks to a more educated public, fewer deaths from foods like chocolate are reported these days. But it is important to keep up with what is currently known about food and its effects on the health of dogs. Grapes and cocoa mulch, for example, were recently found to have harmful effects.
Check back frequently with sources like the ASPCA, or subscribe to “Cold Noses News” and we’ll keep you posted. (You’ll also get a ton of cool dog stuff along with your free registration.)

Of course, being vigilant and taking your pet to the vet right away will help ensure a happy outcome if something unfortunate happens.
For the health and good nutrition of your dogs!

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