Eating a lot of raw onions and garlic is particularly concerning, but smaller amounts over time can also cause issues. So think twice before you give your dog an onion. It's better to be safe than sorry.

Onions and garlic contain compounds that can be harmful to dogs if ingested enough.

Onions and garlic are toxic to dogs in any form, whether fresh, cooked, powdered or dehydrated. They can kill red blood cells in canines, causing anemia. Symptoms of anemia in your dog include weakness, vomiting, little interest in food, and breathing problems.