Certain foods that are safe for humans can be harmful to dogs.

Because dogs have a different metabolism than people, feeding human foods to dogs can be very dangerous for their health and may even be fatal in some cases.

This article reviews seven food items that have been proven toxic to dogs. If you have a dog, it’s important to keep these foods out of their reach.

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1. Avocados

Avocados contain a toxin called persin, which is perfectly safe for human consumption but can be very poisonous to dogs (1).

It is found in avocado fruit, pits, leaves, and bark, so you should avoid giving any part of the plant to your dog.

If a dog eats these, fluid may accumulate in the dog’s lungs and chest. This can make it difficult for them to breathe, which can lead to oxygen deprivation and even death (1).

Fluid can also accumulate in the heart, pancreas, and abdomen, and this can lead to other fatal complications (2).

Additionally, a dog can accidentally swallow an avocado pit, which can cause choking or a blockage in the digestive tract.

Summary

Eating any part of the avocado plant can cause severe health problems in dogs that may result in death.

2. Xylitol

Xylitol is a sugar alcohol often used to sweeten candy, chewing gum, toothpaste, and baked goods.

While deemed safe for human consumption, it can be deadly for dogs.

Eating foods that contain xylitol can lead to a sudden and significant drop in a dog’s blood sugar (3, 4, 5, 6).

Initial symptoms — including vomiting, weakness, depression, difficulty moving, coma, and seizures — often show up within 30 minutes of consumption (1).

Eventually, xylitol can lead to liver damage and death (7).

Summary

Eating foods that contain xylitol can cause a dog’s blood sugar to drop drastically. This can cause health problems, liver failure, and death.

3. Coffee, tea, and other caffeine

Caffeine is naturally found in coffee, tea, cocoa, and guarana, a South American plant.

It is also often added to soft drinks and medications.

Caffeine can speed up the heart rate and stimulate the nervous system in dogs.

Within 2–4 hours of consuming caffeine, dogs may experience restlessness, excessive thirst, a lack of bladder control, vomiting, and diarrhea.

If dogs ingest too much caffeine, they can experience abnormal heart rhythm or lung failure, which can ultimately lead to death.

A dog’s system absorbs caffeine very quickly, leading to mild effects at 9 mg per pound (20 mg per kg) of the dog’s weight and seizures at 27 mg per pound (60 mg per kg) and over (8).

For reference, one typical cup of brewed coffee contains approximately 95 mg (9).

Several cases of death have been reported in dogs due to an overdose of caffeine (10, 11).

Summary

Consuming caffeine can cause abnormal heart rhythm or lung failure in dogs, which can ultimately lead to death. Coffee, tea, and other sources of caffeine should be kept away from dogs.

4. Grapes and raisins

Grapes and raisins can be extremely toxic to dogs.

They can cause rapid kidney failure, which can ultimately be fatal (12).

The toxic compounds in grapes are still unknown, but even small amounts can make your dog sick.

Toxic levels vary from dog to dog, but one study reviewing 169 reports found that some dogs died after eating just a handful of raisins (13).

Therefore, ingestion of any quantity should be taken very seriously.

It is important to note that poisoning can happen as a result of eating grapes and raisins raw or eating them as ingredients in baked goods such as cookies, cakes, and snack bars. Watch for symptoms like vomiting, diarrhea, fatigue, and depression (8).

These may be followed by signs of kidney failure, such as excessive thirst and very little urine production (12).

Summary

Grapes and raisins are highly toxic to dogs. Even very small amounts can lead to kidney failure, which can be fatal.

5. Alcohol and yeast dough

Alcohol is found in a variety of products, including alcoholic beverages, perfumes, mouthwash, paint, varnish, and various cleaning products.

While occasional alcohol consumption is safe for humans, dogs cannot tolerate it, even in small amounts.

Symptoms usually develop within an hour after consumption and include tiredness, depression, lack of muscle coordination, low body temperature, poor breathing, vomiting, and diarrhea.

If a dog consumes too much alcohol, it can result in lung failure, seizures, coma, and even death (14).

Alcohol poisoning in dogs usually happens after accidental ingestion of alcoholic beverages (15, 16, 17).

However, in one case, a dog died of alcohol poisoning after eating a large number of rotten apples (18).

It’s also a concern if a dog eats raw dough that contains yeast. As the yeast cells ferment, they actually produce alcohol, which causes a dog’s blood alcohol level to rise and can ultimately cause alcohol poisoning and death (19, 20).

What’s more, the dough will expand in a dog’s stomach and can cause severe bloating. This puts pressure on the surrounding organs and can make it very difficult for the dog to breathe.

It is important never to feed raw yeast dough or alcohol to your dog. Alcoholic beverages should not be left unattended, and raw dough should be kept well out of reach.

Summary

If a dog consumes alcohol, it can lead to serious health problems and even death. This can also happen if a dog eats raw yeast dough.

6. Chocolate

Chocolate contains the stimulant chemicals theobromine and caffeine, both of which are very difficult for dogs to metabolize.

If a dog eats chocolate, it can cause stomach pain, vomiting, diarrhea, and dehydration.

These symptoms can also progress to more serious problems like heart attacks, internal bleeding, muscle tremors, seizures, and death (21).

The severity of the side effects depends on how large the dog is and how much and what type of chocolate the dog has consumed.

The darker and less sweet the chocolate is, the more toxic it will be to your dog. Unsweetened baker’s chocolate and cocoa powder are among the most dangerous varieties (22).

According to the ASPCA Animal Poison Control Center, dogs may show symptoms after ingesting as little as 18 mg per pound (40 mg per kg) of body weight (23).

In other words, as little as 0.03 ounces (720 mg) of chocolate would be enough to cause toxic symptoms in a 44-pound (20-kg) dog.

It is most common for dogs to experience chocolate poisoning on holidays such as Valentine’s Day, Easter, Halloween, and Christmas — presumably because these are times when people often have chocolate on hand.

No matter the occasion, it is important to always keep chocolate out of reach.

Summary

Eating chocolate can cause a slew of health problems in dogs and can even kill them. The darker the chocolate, the more toxic it is.

7. Salt

Eating too much salt could lead to a condition known as salt poisoning or water deprivation in dogs.

This can cause neurological disorders, cerebral edema, vomiting, diarrhea, depression, tremors, fever, and seizures. It may even be fatal in severe cases (24, 25).

According to the American College of Veterinary Pharmacists, a dose of 2–3 grams per kg of body weight can be toxic to dogs, and 4 grams per kg can be fatal (26).

Because of this, it is not a good idea to give your dog salted foods such as pretzels, popcorn, or chips.

It is also important to make sure your dog always has access to fresh drinking water.

Summary

Eating too much salt can cause water deprivation in dogs, which can be deadly. You should avoid feeding salted foods to your dog and make sure fresh drinking water is always available.

Other foods that may be harmful to your dog

The following foods have not been proven deadly to dogs, but they can still be harmful.

To be safe, you may want to avoid feeding the following foods to your dog:

  • Onions, garlic, and chives. These can damage a dog’s red blood cells and cause anemia. In severe cases, your dog could require a blood transfusion (27, 28).
  • Macadamia nuts. These contain an unknown toxin that can cause weakness, muscle tremors, and vomiting in dogs. Because of their high fat content, macadamia nuts can also lead to pancreatitis, or an inflamed pancreas (29, 30).
  • Apples, apricots, cherries, peaches, and plums. Their seeds or pits contain cyanide, which is poisonous. Eating them can lead to some pretty serious side effects, including digestive problems (31).
Summary

Onions, garlic, chives, macadamia nuts, and fruits with pits may also be harmful to your dog.

What to do if your dog eats a harmful food

The best way to ensure your dog doesn’t eat anything harmful is to keep these foods out of reach.

To minimize the risk, make sure you don’t leave these foods on countertops or tables, in purses, or in other places where your dog could access them.

Keep in mind that different products contain different concentrations of these toxic substances. For instance, the concentration of chocolate in a Snickers bar is different from that of a Ghirardelli bar, so the toxic doses of these two bars would be different.

If you know your dog has ingested something toxic, consult your veterinarian immediately or call the pet poison hotline. Even if the amount they ingested seems less than the toxic dose listed above, it is best to call to get professional recommendations for how to care for your pet.

Treatment will vary depending on your dog’s symptoms and the type of food they were exposed to.

You should never treat or medicate a dog unless a licensed veterinarian advises you to do so.

Summary

If your dog has consumed something toxic, consult your veterinarian or call the pet poison hotline.

The bottom line

Certain foods that are safe for humans, including the seven listed here, can be very harmful to dogs.

The best way to avoid food poisoning in dogs is to feed them only dog food and keep human foods out of reach.

If your dog has eaten something it should not have, contact your vet or call the pet poison hotline immediately.