Courtesy of EGRC

Many common foods are actually harmful or even fatal to dogs. Some of these (listed below) will surprise you. Others are things you would never give your dog purposefully, but now you will be more careful to not let them be in your dog’s reach. And some just need to be limited to small amounts.

Avocados (fruit, pit, and plant) are toxic to dogs. Avocados contain a toxic component called persin, which can damage heart, lung and other tissue in many animals. They are high in fat and can trigger stomach upset, vomiting and even pancreatitis. Symptoms of toxicity include difficulty breathing, abdominal enlargement, abnormal fluid accumulations in the chest, abdomen and sac around the heart. The amount that needs to be ingested to cause signs is unknown. The effects on dogs and cats are not completely understood. GI signs are commonly seen and should be treated symptomatically. In addition, the animal should be monitored closely for other clinical signs related to the cardiovascular system. (This information comes from veterinarians, the American Veterinary Medicine Association, and the ASPCA Animal Poison Control).
Onions destroy red blood cells and can cause anemia, weakness, and breathing difficulty. Even small amounts can cause cumulative damage over time. This includes onions or chives – raw, powdered, dehydrated, or cooked.
Large amounts of garlic cause the same problems as onions. Garlic contains only a small amount of the problematic substance that is in onions. Just as with people, moderation is the key.
Grapes and raisins can cause kidney failure in dogs. As little as a single serving of raisins can kill him. If the dog doesn’t eat enough at one time to be fatal, he can be severely damaged by eating just a few grapes or raisins regularly.
Tomatoes (plant and fruit) contain tomatine, an alkaloid related to solanine. As the fruit ripens, the tomatine is metabolized. Therefore, ripe tomatoes are less likely to be problematic for animals. Clinical signs of poisoning include lethargy, drooling, difficulty breathing, colic, vomiting, diarrhea or constipation, widely-dilated pupils, paralysis, cardiac effects, central nervous system signs (e.g., ataxia, muscle weakness, tremors, seizures), resulting from cholinesterase inhibition, coma and death. (This information comes from veterinarians, and the ASPCA Animal Poison Control Center.) (All parts of the plant except the tomato itself are poisonous to humans, although some people are sensitive to the ripe fruit also.)
Tomatoes also contain atropine, which can cause dilated pupils, tremors, and heart arrhythmias. The highest concentration of atropine is found in the leaves and stems of tomato plants, with less in unripe (green) tomatoes, and even less in ripe (red) tomatoes.
Nutmeg can cause tremors, seizures and death.
Caffeine (from coffee, coffee grounds, tea, or tea bags) stimulates the central nervous and cardiac systems, and can cause vomiting, restlessness, heart palpitations, and even death within hours.
Diet products containing the sweetener Xylitol can cause a sudden drop in blood sugar, resulting in depression, loss of coordination and seizures. Unless treatment is given quickly, the dog could die.
Macadamia nuts can cause weakness, muscle tremor and paralysis. These symptoms are usually temporary.
Walnuts. When dogs eat the seed hulls, they can get an upset stomach and diarrhea. The real problem is the fungus or mold that attacks walnuts after they get wet (from rain or sprinklers), which produces toxins. If the fungus or mold is ingested by your dogs, they can become very ill and possibly die. Signs that should alert you to walnut poisoning are vomiting, trembling, drooling, lack of coordination, lethargy, loss of appetite, and jaundice indications such as yellowing eyes and gums. Severely affected dogs can produce blood-tinged vomit or stools. Dogs can take several days to exhibit serious signs of illness.
Chocolate can cause seizures, coma and death. Baker’s chocolate is the most dangerous. The darker the chocolate, the more dangerous it is. But any chocolate, in large enough amounts, can kill a dog. An ounce of chocolate can poison a 30-pound dog, and many dogs will happily consume more than this. The symptoms may not show up for several hours (and so might make you think all is well), with death following within twenty-four hours. A dog can consume milk chocolate and appear to be fine because it is not as concentrated, but it is still dangerous.
Apple seeds, cherry pits, peach pits, pear pips, plums pits, and apricot pits contain cyanide, which is poisonous. While a few apple seeds may not cause a problem, the effects can accumulate over time if they are given to dogs regularly. Dogs should not be allowed to chew on a peach pit, cherry pit, apricot pit, or plum pit. Chewing can allow ingestion of cyanide. Chewing could also result in the pit being swallowed, causing continuous exposure to cyanide, or could cause the dog to choke.
Too much salt can cause kidney problems. Also, large breeds of dogs that eat salty food may then drink too much water and develop bloat, which is fatal unless emergency treatment is given very quickly.
Too much fat or fried foods can cause pancreatitis.
Ham and bacon contain too much fat and too much salt, and can cause pancreatitis. Also, large breeds of dogs that eat salty food may drink too much water and develop a life-threatening condition called bloat. This is where the stomach fills up with gas and within several hours may twist, causing death.
Raw liver or too much cooked liver (three servings a week) can lead to vitamin A toxicity. This can cause deformed bones, excessive bone growth on the elbows and spine, weight loss, and anorexia. Check the label of your canned dog food to be sure that it does not contain liver if you are giving your dog liver also.
Wild mushrooms can cause abdominal pain, drooling, liver damage, kidney damage, vomiting, diarrhea, convulsions, coma, or death.
Raw egg whites contain a protein called avidin, which can deplete your dog of biotin, one of the B vitamins. Biotin is essential to your dog’s growth and coat health. The lack of it can cause hair loss, weakness, growth retardation, or skeleton deformity. Raw egg yolks contain enough biotin to prevent the deficiency, so this is not a problem with raw whole eggs. Raw egg yolks could contain salmonella, so you should get your eggs from a reliable source or cook the eggs.
Grains should not be given in large amounts or make up a large part of a dog’s diet, but rice is generally safe in small amounts.
Cooked bones can splinter and tear a dog’s internal organs.
Dogs can’t digest most vegetables (carrots, green beans, lettuce, potatoes or yams) whole or in large pieces. Potato peels and green potatoes are dangerous.
Dairy products are high in fat, which can cause pancreatitis, gas and diarrhea. A small amount of non-fat, plain yogurt is usually safe.
Pennies made from the 1980s to today contain zinc, which can cause kidney failure and damage to red blood cells. A dog that consumes even one penny can become quite sick, or even die, if the penny is not removed.

“My dog ate ______ lots of times and didn’t die, so ______ don’t kill dogs.” That logic is no better than “My dog runs in the street all the time and has never been hit by a car, so dogs never get hit by cars.”