4. Garlic & Onion

Widely known to make your breath stink, Onions and Garlic can be far more effective to your dog than you can imagine. Consumed either by cooked, raw, powdered or dehydrated they can destroy the red blood cells. This can cause anemia, weakness, breathing difficulties and vomiting. Although, certain sources say that a small dose has a marginal effect it is better to go vigilant on this one.