1. Macadamia nuts

It’s unclear exactly why macadamia nuts are toxic to dogs, but when eaten they can cause limb weakness, vomiting, pancreatitis, tremors, and lethargy. Macadamia nut poisoning is often milder than some other items on this list, but it could still require veterinary care.

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While macadamia nuts aren’t a super common household food, they can be in many baked goods or trail mixes, like macadamia nut cookies. So it’s important to be careful about giving your dog a piece of a cookie or leaving them out and within reach. However, macadamia nuts do not seem to be harmful to cats, though.

2. Bread dough (yeast)

Raw bread dough (and the yeast inside it) is doubly bad for cats and dogs: The unbaked bread dough can expand in the stomach, while the yeast produces alcohol. The rising dough can bloat or twist the pet’s stomach, potentially causing vomiting, retching, weakness, an abnormal heart rate, collapse, and death.

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The yeast, on the other hand, can give your pet alcohol poisoning and subsequent drops in blood sugar, blood pressure, and body temperature. If your pet is really intoxicated, they can suffer seizures and respiratory failure. While you might like to eat bits of cookie dough, don’t let your pet eat dough.

3. Avocados

Avocados may be beloved by millennials, but they are not beloved by pets. An avocado’s pit is enormous and evolved to be eaten by giant sloths, so it could do serious damage to a dog or cat if swallowed. Plus the avocado’s high-fat content could give your pet pancreatitis. Avocadon’t feed this to your pet!

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On top of that, avocados also have a toxin called persin, which tends to be mildly poisonous for dogs and cats but can be deadly to birds, horses, cows, goats, sheep, and other animals. So, never feed a bird or hooved animal an avocado, no matter how trendy the toast.

4. Nicotine, tobacco, secondhand smoke

Unlike many of the items on this list, nicotine is bad for both humans and pets. However, you’re probably not going to find your cat smoking a cigarette on the patio. What could happen is your dog eating stray cigarette butts and unattended nicotine gum.

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Often, the pet will vomit up the nicotine if it’s a small enough amount, but it is still good to contact the vet regardless. Nicotine can influence your pet’s heart rate and cause them to have tremors and weakness. On top of that, secondhand smoke and any tobacco residue left on hands, clothing, or furniture are harmful to pets. 

5. Cherries, peach pits, apple seeds

While most humans have the sense to spit out a cherry pit, who’s to say your dog won’t just gobble the thing whole? It’s best to keep dogs and cats away from cherries. Their pits, stems, and leaves contain cyanide, an enzyme that prevents cells from taking in oxygen. Enough cyanide can be lethal.

Dog cherries pits toxic pets
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A single cherry pit may not give your pet cyanide poisoning, but it could lodge itself in the animal’s digestive tract and create a blockage. If this happens, your dog might vomit, eat less food, and poop less often. In addition to cherries, peach pits and apple seeds also contain cyanide.

6. Wild mushrooms

As there are thousands of different types of mushrooms, many of them are not toxic to pets. However, some are severely toxic and can be deadly. Unfortunately, it’s difficult to tell different mushroom types apart if you aren’t trained to. Just like you shouldn’t be eating random mushrooms off the forest floor, neither should your pet.

Dog mushroom pet poison toxic
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So if you’re taking your dog (or cat, or ferret) for a walk in the woods, don’t let it eat any wild mushrooms. Dogs can’t tell which ones are toxic. Toxic mushrooms can affect an animal’s gastrointestinal system, central nervous system, liver, and kidneys.

7. Alcohol

While you may want to enjoy a glass of wine with your cat as a chill night in, don’t give the kitty (or dog, horse, bird, or cow) any alcohol. Animals can get alcohol poisoning much easier than humans, so even a small amount of alcohol from a rum-soaked cake could be dangerous.

Cat and wine alcohol bad for pets
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Symptoms and signs of alcohol poisoning in pets include lethargy, drooling, vomiting, weakness, and collapse. On top of this, it can give your pet low blood sugar, blood pressure, and body temperature. Despite the name, “cat wine” doesn’t have any alcohol in it, but has catnip instead.

8. Golden pothos plant (Devil’s Ivy)

The golden pothos (or Devil’s ivy) is a popular household plant, but if your cat or dog has a habit of munching on plants, you should keep this one out of reach or out of the house. It generally isn’t severely toxic, but it can irritate your pet’s mouth and gastrointestinal tract if eaten.

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Very rarely, it can even cause the pet’s airway to swell and make breathing difficult. Pothos is toxic because of the calcium oxalate crystals it contains. So grab yourself one of those cute hanging planters if you’re set on keeping a golden pothos in your house.

9. Tylenol (acetaminophen)

It is very risky to give your cat or dog medicines meant for humans. What may work just fine in a human body can be severely toxic to pets. For example, acetaminophen (more commonly known as Tylenol) is great for pain relief in people but can be deadly to animals.

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Animal bodies often break down (aka metabolize) drugs differently than human bodies do, causing them to have a very different reaction. For cats, any amount of acetaminophen/Tylenol is poisonous. For dogs, it depends on their weight and health, but to be safe you probably shouldn’t give them any of it.

10. Caffeine

While caffeine is a crutch for many an office-goer and class-taker, it shouldn’t be given to cats or dogs. Tea, soda, coffee, energy drinks, and caffeine supplements could cause hyperactivity, high blood pressure, vomiting, and a spiked heart rate, among other symptoms.

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In some cases, caffeine poisoning can be bad enough to cause seizures and death. Let’s be honest, your pup and kitty are probably energetic enough, so keep the caffeinated foods and beverages out of sight and out of reach. But if you want to get your cat excited, offer them catnip instead. And for your dog, the word “walk” will probably suffice.

11. Essential oils

Essential oils may be all the rage, but you have to be careful when using them around cats, who have a hard time metabolizing these toxins. Cats can absorb essential oils through their skin, so you should keep all essential oils out of reach. However, the type of oil does influence how it affects your cat.

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Eating or touching essential oils is dangerous for cats, but breathing them in can be, too. Watch for coughing, wheezing, labored breathing, panting, or fast breathing in your cat. If your cat looks like it’s about to cough up a hairball or vomit and nothing comes out, this could be a sign of respiratory issues.

12. Garlic

Garlic may be delicious and smell amazing, but it’s very bad for cats and dogs. Enough garlic can damage a cat’s red blood cells, leading to anemia. On top of that, it can also mess with the animal’s gastrointestinal tract, potentially causing nausea, drooling, vomiting, abdominal pain, and diarrhea.

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These symptoms of garlic poisoning aren’t always immediate and can appear several days after the pet eats garlic. Tiny amounts may be safe, but large amounts are generally toxic. Dracula may be famous for his garlic aversion, but don’t count on your pet’s behavior to keep them away from this food. Don’t feed them garlic and keep a lookout for garlic powder in food labels.

13. Onions

Onions are dangerous for pets in the same way as garlic. The two are part of the same plant family, which also includes chives and leeks (so don’t feed those to your pet either). Garlic is the most toxic of the bunch, but you should keep your pet away from all of them.

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While it’s easy enough to not feed your cat a chunk of garlic or piece of onion, powdered versions of these are in a lot of foods, like chips, so keep an eye on those ingredient lists. Also, don’t let your pet sneak a piece of onion while your eyes are filled with tears.

14. Grapes and raisins

Grapes and raisins may seem like benign snacks, but they can be very toxic to dogs (possibly cats and ferrets, too). It’s unknown exactly how, but grapes and raisins can cause kidney failure in dogs. Also, it doesn’t seem to matter how much the dog eats. No amount has yet been proven safe to eat.

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Be careful what you feed your dog since raisins can be hiding in anything from trail mix to snack bars. Also, some cookies and breads have raisin paste or raisin juice. Currants and sultanas are related to grapes, as well, so don’t let your dog eat those either.

15. Lilies

Plenty of plants are toxic to cats, but lilies are certainly one of the most dangerous. Just a leaf or a bit of pollen from a lily can be enough to kill a cat. Every part of a lily is dangerous and can cause kidney failure within one to three days. There’s no real antidote for this poison, but if you get your cat to the vet quickly, they can possibly save it.

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Lilies aren’t so toxic to dogs, but they can cause gastrointestinal issues. Also, there are a few kinds of lily that don’t cause kidney failure in cats, including the peace and calla lilies, but they can still be mildly poisonous.

16. Cleaning supplies and detergents

Just as you wouldn’t feed yourself (or your kid) cleaning supplies, don’t feed them to any of your pets. Or, since that’s fairly obvious, don’t keep cleaning supplies in places where a dog or cat could consume them. For example, if you’re cleaning a stain or spill, keep your curious kitty and careless dog away.

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Or, if you’re cleaning the toilet bowl, don’t let your pet near it until it’s done. This also applies to laundry products, like fabric softeners and dryer sheets. These various products can give your pet ulcers and other problems, depending on the cleaning or detergent product.

17. Chocolate

Chocolate contains two compounds that are bad for dogs: theobromine and caffeine. Both can interfere with the heart rate and nervous system of the animal. However, the toxicity of the chocolate depends on the kind eaten: cocoa powder is the most toxic, while milk and white chocolate are the least. 

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For a small dog, one Hershey’s milk chocolate bar can be dangerous but a small crumb of a chocolate cake probably won’t be lethal. While the dangerous effects depend on the type of chocolate, amount eaten, and the dog in question, keep the pooch away from chocolate as a rule.

18. Xylitol (sweetener)

One of the more common causes of dog poisoning is xylitol, a sugar-free sweetener. It can be found in some chewing gums, candies, toothpastes, mints, sauces, supplements, and other things. So you should look carefully at sugar-free labels and keep these items away from where your dog can get them.

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Enough xylitol can be deadly to dogs by dropping their blood sugar to life-threatening lows. It can also make a dog’s liver fail. The symptoms depend on how much xylitol the dog consumed and can show up in the form of weakness, vomiting, seizures, tremors, and collapse. Sugar-free isn’t always good.

19. Monstera plant

Monstera plants may have taken the internet by storm and become a favorite house plant, but just like the golden pothos, they are moderately toxic to cats and dogs. The two plants are in the same family (Araceae) so they both have the same irritating calcium oxalate crystals.

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This very holey plant goes by many names, including Monstera, split-leaf philodendron, cut-leaf philodendron, and Swiss cheese plant. If your pet likes to eat plants, then this plant trend is probably not for you. Sorry, but you’ll just have to get one of those framed photos of it for your apartment, instead!

20. Tomato plants

Generally, the fleshy fruit of a ripe tomato is safe for dogs to eat, but the rest of the plant is not. The tomato plant’s stem and leaves contain solanine, which can be toxic to dogs. So if you have tomato plants in your garden, make sure your dog doesn’t eat them.

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Eating the plant can lead to tremors, seizures, and muscle weakness, among other things. If you do have a tomato plant, you should consider fencing it off or supervising your dog when he or she is near the garden. Your dog has to say tomat-no to tomato plants.

21. Azaleas and rhododendrons

Azaleas and rhododendrons are very pretty, often with pink flowers, but that beauty doesn’t matter when your pet’s life is in danger. There are about 1,000 different plant species that are called by these names, which can be severely toxic to cats and dogs depending on how much the animal eats.

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The grayanotoxins in these plants interfere with sodium channels in the body and can impact skeletal and cardiac muscle. Symptoms of azalea and rhododendron poisoning can show up in gastrointestinal, cardiovascular, and central nervous system signs. This includes everything from drooling to an abnormal heart rate to a coma. 

22. Zinc (pennies)

Just like you wouldn’t want your kid eating pennies, don’t let your pet do it either. Coins, nuts, bolts, and even topical ointments can contain the element zinc, which is poisonous to dogs, cats, and birds. Some coins contain more zinc than others, like pennies for instance, so the possible toxicity depends on which coin was eaten.

Pennies bad for dogs
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When consumed, zinc is broken down and absorbed in the animal’s stomach. From there, it can destroy red blood cells, damage the liver, and induce kidney or heart failure. Weakness, pale gums, vomiting, and discolored urine are just some of the signs of zinc poisoning.

23. Sago palms

Sago palms are tropical plants that are sometimes used as Bonsai houseplants or decorations elsewhere. All parts of the plant are toxic, but especially their seeds are dangerous to cats and dogs. The compound cycasin in sago palms can cause liver failure in dogs when eaten.

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Gastrointestinal signs of poisoning can show up in a dog as quickly as 15 minutes after it eats part of a sago palm. Within a few hours to a few days, other signs may be visible in your pet. This is a very severely toxic plant to pets and the survival rate is about 50%.

24. Spinach

While a small amount of spinach is probably fine, very large quantities or long-term consumption could lead to kidney issues for your dog. Spinach has a lot of oxalic acid in it, which can damage the kidney by interfering with calcium absorption in the body.

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Spinach’s safety for dogs is a fairly controversial topic since the food does contain a lot of nutrients. However, your dog food should be providing all those same good nutrients. It’s best to consult a veterinarian about feeding your dog spinach before you do so, considering its possible kidney effects. Perhaps your dog should not eat his greens.

25. Ibuprofen

Sure popping a couple ibuprofen (aka Advil) pills is great for human pain relief, but it is definitely toxic to cats and dogs. If your dog really needs pain relief, there are anti-inflammatory drugs specifically made for them that you could consult your veterinarian on. There are none for long term use in cats currently because they are very sensitive.

Advil ibuprofen pills bad for pets
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When eaten, ibuprofen can cause your pet to have stomach ulcers, diarrhea, and abdominal pain (among other symptoms) in small doses. In large doses, ibuprofen can cause kidney failure, liver failure, neurological problems, and death. Luckily, the child lock on pill bottles doubles as a pet lock.