Most people know that chocolate is bad for dogs. The toxic agent in chocolate is theobromine. It's in all kinds of chocolate, even white chocolate. The most dangerous kinds, though, are dark chocolate, chocolate mulch, and unsweetened baking chocolate. Eating chocolate, even just licking the icing bowl, can cause a dog to vomit, have diarrhoea, and be excessively thirsty. It can also cause abnormal heart rhythm, tremors, seizures, and death.
2. Grapes, Raisins
Grapes and raisins have often been used as treats for dogs. But it's not a good idea. Although it isn't clear why, grapes and raisins can cause kidney failure in dogs and just a small amount can make a dog ill. Repeated vomiting is an early sign. Within a day, the dog will become lethargic and depressed. The best prevention is to keep grapes and raisins off counters and other places your dog can reach.
3. Garlic, Onions
Onions and garlic in all forms -- powdered, raw, cooked, or dehydrated -- can destroy a dog's red blood cells, leading to anaemia. That can happen even with the onion powder found in some baby food. Just eating a large quantity once or eating smaller amounts regularly can cause poisoning.
4. Alcoholic Drinks
Beer, liquor, wine, and foods containing alcohol - none of it is good for your dog. That's because alcohol has the same effect on a dog's liver and brain that it has on humans. But it takes far less to do its damage. Just a little can cause vomiting, diarrhoea, central nervous system depression, problems with coordination, difficulty breathing, coma, even death. The smaller the dog, the greater the effect.