Grapes and raisins are extremely toxic to dogs and the results of their consumption can be devastating. The biggest risk is rapid kidney failure after eating, vomiting or diarrhea. Death from kidney failure may occur within three to four days, so don't take any risks if you love your dog.
Coffee:
Don’t share coffee with your dog, just don’t. They have such a relaxed life and so much natural energy that they really don’t need it. Coffee contains a stimulant known as Methylated Xanthine that stimulates the nervous system in dogs. This can make the dog restless in a bad way, and may lead to vomiting, heart palpitations or even death.
Apple core:
An uneaten apple core thrown on the ground or in the trash can be a real danger to your dog. The apple core, and many other fruit cores, contain cyanogenic glycosides, also known as cyanide. It may cause dizziness, breathing difficulty, seizures, collapsing, hyperventilation and shock.