NO-GO: Vegetables that aren’t safe for dogs (you’ll be surprised!)

by | Dog Care, Dog Food, Dog Safety

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My dog loves chewing on fresh vegetables but I know there are some vegetables I need to keep far away from him. I did some research to find out what vegetables are dangerous for dogs and why, and here’s what I found…

Dogs can eat most vegetables in moderation, but there are some vegetables that a dog should never eat, such as corn on the cob, garlic and all onions. These are either toxic to dogs and even a small amount can make them ill, or there is a risk that the vegetable may choke the dog or block its intestine.

Click here if you’re looking for a list of vegetables that dogs can safely eat.

Click here to find out if it’s cheaper to make your own dog food…

Always consult your veterinarian for advice before adding vegetables to your dog’s diet. Dogs do not need to eat vegetables if they are on a balanced diet. Too many vegetables can do more harm than good, especially if your dog has health issues such as diabetes or kidney stones.

Table of Contents

    Can dogs eat corn on the cob?

    Dogs can eat corn kernels (the yellow fleshy pieces of corn) in moderation but not the corn cob (the hard, white core that the kernels grow on). If a dog swallows a corn cob, it could choke or the cob could get stuck in the dog’s bowel and require surgery.
    It is simply too risky to feed a dog corn on the cob, especially if the dog eats quickly and has a tendency to gulp down their food – click here to see my article on how to slow down greedy eaters (I have one too!).

    Corn on the cob with lables showing what parts dogs cannot eat
    Corn cobs are not safe for dogs to eat, but dogs can safely eat the soft kernels off the cob.

    Can dogs eat garlic?

    Garlic is toxic to dogs so dogs should never eat it. Eating some garlic can cause vomiting and diarrhea. A lot of garlic can make a dog’s red blood cells burst, making the dog anemic so oxygen doesn’t get carried around the body as it should. An anemic dog tires easily, loses their appetite, and loses blood through the stool, urine, vomit, or nose.
    A little garlic now and then probably won’t have any harmful side effects for a dog. But a lot of garlic at once or garlic eaten over a period of time could cause problems.
    We know that onions are poisonous to dogs (see below). Garlic actually falls into the onion family, but it’s five times more toxic than regular onions.
    It’s best not to give any garlic to a dog.

    Can dogs eat green tomatoes?

    Green, unripe tomatoes and all green tomato leaves and stems are not good for dogs to eat. They contain alpha-tomatine, which is poisonous to dogs in high amounts. The highest levels of tomatine are in the tomato plant’s flowers and small green stems.
    As tomatoes ripen, and turn from green to red, tomatine levels decrease and may disappear completely in a red tomato that’s been on the plant for several days.
    Ripe, red tomatoes are safe in moderation – see the full list of vegetables that are safe for dogs to eat HERE.
    But it does take a lot of green tomatoes to have any effect on a dog. The first signs of harm from green tomatoes are vomiting and/or diarrhea. These are a dog’s natural reactions to get the tomatoes out of its system.
    If the vomiting and diarrhea persist, the dog may need the help of a vet for a check.

    Picture of green tomatoes, stalks and leaves with a label showing what parts dog cannot eat
    Green tomatoes and the stalks and leaves of tomato plants are toxic to dogs. Dogs should never eat green tomatoes.

    Can dogs eat leeks?

    Dogs should not be given leeks. Leeks are part of the onion family and may cause vomiting, abdominal pain, and/or diarrhea in dogs. Large amounts may damage a dog’s red blood cells and need a vet’s assistance. Want to know something interesting? Japanese dog breeds tend to be more sensitive to the negative effects of leeks than others. Some examples of Japanese dog breeds are Hokkaido, Akita Inu, and Shiba Inu.

    Pictures of Japanese dog breeds with their names

    Can dogs eat onions?

    Onions are toxic to dogs if a dog eats a large amount in one go or eats onions over a long period of time. Symptoms of onion poisoning could show up several days after the dog eats the onions. Onion poisoning may cause diarrhea, vomiting and abdominal pain, but more severe poisoning may burst red blood cells in the dog, making the dog anemic.

    Signs of anemia in dogs include:

    • Pale gums
    • Lack of energy / lethargy
    • Weakness
    • Elevated heart rate
    • Collapse

    It’s best to never feed a dog any onions, even a small amount of onions that might be hidden in food you give your dog as a treat.

    Can dogs eat potatoes?

    Raw potatoes and potato plants can be toxic to dogs. If a dog eats enough of any part of a raw potato or its plant, the dog could start vomiting or get diarrhea and abdominal pain. If the dog eats a lot of raw potato or plant, and the dog is small and/or has health issues, the dog could experience more dangerous side effects.

    These side effects could include heart problems, hypothermia (low body temperature), paralysis, or seizures.

    If a dog swallows a whole raw potato or large chunk of raw potato, the potato could choke the dog or get stuck in the dog’s intestine.

    If you want to give your dog some potato, be sure to cook it beforehand. Don’t use any fat, seasonings, or salt.

    You can see more about how to safely feed a dog potatoes by checking out the full list of vegetables that dogs can eat HERE.

    Can dogs eat rhubarb?

    Dogs should not eat rhubarb. This red vegetable often causes diarrhea, vomiting, and/or shivering from sugar overload if a dog eats a lot of rhubarb in one go. But if a dog eats too much or any of the green rhubarb leaves there could be much more serious side effects.

    Rhubarb leaves contain oxalic acid, which is poisonous to dogs. If a dog eats enough leaves, the oxalic acid may give the dog seizures, tremors, kidney failure, and other health problems.

    Can dogs eat shallots?

    Dogs cannot eat shallots. Shallots are part of the onion family and all onions are toxic to dogs. Shallots can cause vomiting and panting in dogs. If enough shallots are eaten in one sitting or over time, the dog may become anemic.

    Symptoms of anemia in dogs include:

    • Pale gums
    • Lack of energy / lethargy
    • Weakness
    • Elevated heart rate
    • Collapse

    Onion poisoning symptoms may take up to 5 days to show in a dog, so if your dog has eaten shallots keep a close eye on them. If the above symptoms start to show, it’s best to take your dog to the vet for help.

    Can dogs eat wild mushrooms?

    Dogs cannot eat wild mushrooms. While only a few wild mushrooms are poisonous, the ones that are poisonous can kill a dog very quickly. It’s better not to take a chance and keep dogs away from all wild mushrooms.

    Wild mushrooms include mushrooms on walking trails, in forests, near lakes, and in your own backyard! ‘Wild mushrooms’ are any mushrooms that are not bought at a store for consumption.

    Different mushrooms cause different symptoms and reactions in dogs when eaten.

    The most common symptoms of mushroom poisoning are:

    • Abdominal pain
    • Vomiting
    • Diarrhea
    • Drooling
    • Seizures
    • Lethargy
    • Watery eyes

    But toxic wild mushrooms can cause a coma, liver failure, kidney failure, and even death.

    It’s best to watch your dog closely when out walking and always remove mushrooms from your backyard.

    I'm Monique. I love animals and everything about them. "Ayo" means happy, and this is where I share all I know about having happy, healthy pets so you can have happy pets too.

    Ayo Pets participates in the Amazon Services LLC Associates Program, the ShareASale affiliate program, and other affiliate programs. This means that if you buy a product or service through one of our links, we may receive a small commission from the sale for referring you. Thank you for your support!


    Monique has had pets all her life and will have them for the rest of it.

    She currently has 4 adopted fur kids.

    Monique loves researching and sharing what she finds out about taking the best care of animals.

    Ayo is an African word for ‘happy’, which is why this site is called Ayo Pets (Happy Pets).


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