The following list comes from the American Kennel Club:
Chocolate – No. This isn’t just an old wives’ tale. Chocolate contains a very toxic substance called methylxanthines, which are stimulants that stop a dog’s metabolic process. Even just a little bit of chocolate, especially dark chocolate, can cause diarrhea and vomiting. A large amount can cause seizures, irregular heart function, and even death. Do not have chocolate in an accessible location. If you’re dog does ingest chocolate, contact a veterinarian or Pet Poison Helpline as soon as possible.
Cinnamon – No. Cinnamon and its oils can irritate the inside of pets’ mouths, making them uncomfortable and sick. It can lower a dog’s blood sugar too much and can lead to diarrhea, vomiting, increased, or decreased heart rate and even liver disease. If they inhale it in powder form, cinnamon can cause difficulty breathing, coughing, and choking.
Garlic – No. Like onions, leeks, and chives, garlic is part of the Allium family, and it is five times more toxic to dogs than the rest of the Allium plants. Garlic can create anemia in dogs, causing side effects such as pale gums, elevated heart rate, weakness, and collapsing. Poisoning from garlic and onions may have delayed symptoms, so if you think your dog may have eaten some, monitor him or her for a few days, not just right after consumption.
Ice cream – No. As refreshing of a treat ice cream is, it’s best not to share it with your dog. Canines don’t digest dairy very well, and many even have a slight intolerance to lactose, a sugar found in milk products. Although it’s also a dairy product, frozen yogurt is a much better alternative. To avoid the milk altogether, freeze chunks of strawberries, raspberries, apples, and pineapples and give them to your dog as a sweet, icy treat.
Almonds – No. Almonds may not necessarily be toxic to dogs like pecans, walnuts and macadamia nuts are, but they can block the esophagus or even tear the windpipe if not chewed completely. Salted almonds are especially dangerous because they can increase water retention, which is potentially fatal to dogs prone to heart disease. Read More >
Macadamia nuts – No. These are some of the most poisonous foods for dogs. Macadamia nuts, part of the Protaceae family, can cause vomiting, increased body temperature, inability to walk, lethargy, and vomiting. Even worse, they can affect the nervous system. Never feed your pets macadamia nuts.