Unsafe Vegetables for Dogs

Dog should never eat vegetables in the onion and garlic family due to their ability to destroy red blood cells. When it comes to garlic, even a teaspoon can be dangerous to dogs that weigh less than 10 pounds. Not just raw onions and garlic are toxic; you should also avoid feeding your dog any food that includes ingredients from the garlic and onion family, in whole or dehydrated forms. For example, never feed your dog spaghetti sauce, even if it was made with garlic powder. Symptoms of toxicity include increased heart rate, lethargy, vomiting and diarrhea, and possibly bloody urine. Take your dog to an emergency vet immediately for treatment, which may include blood transfusions. Without treatment, your dog may experience kidney damage or death.

Though they are known as a fruit, tomatoes are technically a vegetable that can be poisonous to dogs. While ripe tomatoes aren't toxic to dogs, those that are unripe and the plants themselves can be. Unripe tomatoes, and especially tomato plants, contain unsafe levels of tomatine, which can affect the nervous system, kidneys and digestive tract. Symptoms may include tremors, seizures, vomiting, dilated pupils. If you notice any of these symptoms or suspect that your dog has eaten a tomato plant or an unripe tomato, take him to the vet immediately. Too much tomatine can kill a dog.

Raw, green potatoes are toxic to not just humans; they're toxic to dogs, too. Green potatoes contain solanum alkaloids, which can cause stomach and heart problems along with headaches and dizziness. Cooked potatoes, on the other hand, are thought to be safe for dogs; they often serve in dog foods as a carbohydrate source. If your dog eats a raw, green potato, take him to the vet for treatment if you notice any of these symptoms.

White mushrooms, the most commonly used in the kitchen, are perfectly fine for dogs. However, wild mushrooms are a different story. While symptoms of ingestion can vary depending on the kind of mushroom, a dog may experience anxiety, restlessness, stomach issues, trouble breathing or coma. In the worst case, when a dog consumes a death cap mushroom -- Amanita phalloides -- he will experience bloody diarrhea, stomach cramps, fever and dehydration; death can result in three to seven days. If your dog has eaten a mushroom, collect a sample of the mushroom and rush your dog to an emergency vet immediately.

Though ruled in court to be a fruit in 1947, rhubarb is technically a vegetable and is poisonous to dogs. Like tomatoes and raw, green potatoes, rhubarb can damage the nervous system, leading to tremors, heart arrhythmia and seizures. If your dog eats rhubarb, a vet visit is necessary.