Nutmeg - Nutmeg contains a compound called myristicin, which, when ingested by dogs in large quantities, can lead to rapid heart rate, hallucinations, and seizures.
Garlic - Garlic can be fatal to dogs due to a compound called thiosulfate that damages red blood cells.
Rhubarb - Rhubarb can cause kidney failure in dogs due to an antinutrient called oxalic acid.
Onions - Onions can be poisonous to dogs due to the thiosulfate they contain. Certain dog breeds are more vulnerable, and their size makes a huge difference.
Caffeine - A small amount of caffeine won't do any harm, but if your dog swallows a handful of coffee beans or tea bags then it can pose serious danger.
Green tomatoes - Once tomatoes are ripe, then they're safe for dogs. But green tomatoes or not fully ripe red tomatoes can be toxic for dogs due to a substance called solanine.
Spinach - Spinach contains a high amount of oxalic acid, a substance known to interfere with dogs’ ability to absorb calcium. This can cause kidney damage if consumed regularly.
Cat food - Cat food won't poison your dog immediately, but it can lead to pancreatitis and other health complications over time, causing organ damage and even death.
Potatoes - Potatoes are toxic for dogs due to them containing solanine. It blocks a chemical called acetylcholine, which dogs need to transmit nerve impulses.
Tobacco - Tobacco isn’t technically a food, but it's something ingested by humans, which can be extremely lethal for dogs if they manage to chew on cigarettes.