Most dog owners understand the basics of pet care: taking your dog on a walk for exercise, grooming your dog to keep it clean, and keeping your dog safe from things that could harm it.

Those dangerous items could include tiny pieces of plastic or dog toys that come apart easily. But you also have to keep an eye on the type of food you leave within reach of your dog, especially if your dog is a large dog that can reach counter surfaces. Many foods that humans regularly eat can be toxic to dogs.

Most Dangerous Foods for Dogs

When a dog eats a food that could be toxic to it, several different symptoms can arise. Your dog may vomit or suffer from diarrhea, which could be a sign of some damage occurring to internal organs. Or your dog may have a couple of days of lethargy and lack of appetite before it begins acting normally again. Here are five of the most toxic foods for dogs, and the signs you may see if your dog has eaten them.

1. Alcohol and ethanol. Much in the same way that alcohol affects a human, it will also affect a dog. However, the alcohol works much more quickly in the dog’s system, causing potential damage to its health. The alcohol can cause problems with the dog’s respiratory system, nervous system, and blood chemicals.
2. Chocolate. Your dog may show a general lethargy and nervous system problems after ingesting chocolate. The theobromide in chocolate also will cause damage to the dog’s heart, lungs, and kidneys. If you believe your dog has eaten chocolate, especially dark chocolate, you need to contact your veterinarian immediately.
3. Coffee and tea. The caffeine in coffee and tea can cause serious health problems in dogs, especially when ingested in large quantities. A dog may vomit or suffer from tremors or seizures after drinking a lot of coffee. If your dog does vomit from this or other toxic foods, be sure you know how to handle it!
4. Grapes and raisins. Even only a few grapes or raisins can make your dog very sick and could be fatal. A dog will vomit and be dehydrated after ingesting grapes. Eventually the dog will suffer kidney failure if not treated. Contact your veterinarian if your dog has eaten grapes or raisins.
5. Macadamia nuts. If the dog only eats a few of these nuts, they likely will not cause long-term harm to the dog’s health. Instead, you may see your dog suffering from weakness, vomiting, and joint pain. Symptoms from ingesting macadamia nuts may not show up in your dog for up to two days, so keep an eye on the dog if you suspect it has eaten a lot of these nuts.
6. Understanding Food Toxicity in Dogs

Keep in mind that the toxic foods listed in the infographic below will affect dogs in different ways, even dogs from the same breed. The dog’s weight and size will also play a role in determining how much of a toxic food it can ingest before showing symptoms. Now that doesn’t automatically mean that a large dog could eat more chocolate safely than a small dog, because the breed of the dog plays a role too. Individual dogs will react differently to each of these toxic foods, so even a tiny amount of chocolate could cause a large dog to become very ill.

The best way to ensure that your dog doesn’t suffer problems with food toxicity is prevention. Take care to keep all human foods out of reach of your dog, and clean up dishes and cups that may have contained toxic foods before you dog is tempted to lick them clean. Unfortunately, dogs don’t naturally stay away from foods that are dangerous to them. So you’ll need to take precautions to ensure your dogs don’t have the chance to eat those foods!